diff --git a/package-lock.json b/package-lock.json
index 7793b8a..d538c33 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -2258,17 +2258,29 @@
       "integrity": "sha512-/1FpHvmKmKo2Z6CCza2HfkrKvKhU7Rq4nvyX1FOherdTrdTufhVrJbCrcrIqgqUCI+BG6JC2rlY4z5QA1G0NOw=="
     },
     "elliptic": {
-      "version": "6.4.1",
-      "resolved": "https://registry.npmjs.org/elliptic/-/elliptic-6.4.1.tgz",
-      "integrity": "sha512-BsXLz5sqX8OHcsh7CqBMztyXARmGQ3LWPtGjJi6DiJHq5C/qvi9P3OqgswKSDftbu8+IoI/QDTAm2fFnQ9SZSQ==",
+      "version": "6.5.4",
+      "resolved": "https://registry.npmjs.org/elliptic/-/elliptic-6.5.4.tgz",
+      "integrity": "sha512-iLhC6ULemrljPZb+QutR5TQGB+pdW6KGD5RSegS+8sorOZT+rdQFbsQFJgvN3eRqNALqJer4oQ16YvJHlU8hzQ==",
       "requires": {
-        "bn.js": "^4.4.0",
-        "brorand": "^1.0.1",
+        "bn.js": "^4.11.9",
+        "brorand": "^1.1.0",
         "hash.js": "^1.0.0",
-        "hmac-drbg": "^1.0.0",
-        "inherits": "^2.0.1",
-        "minimalistic-assert": "^1.0.0",
-        "minimalistic-crypto-utils": "^1.0.0"
+        "hmac-drbg": "^1.0.1",
+        "inherits": "^2.0.4",
+        "minimalistic-assert": "^1.0.1",
+        "minimalistic-crypto-utils": "^1.0.1"
+      },
+      "dependencies": {
+        "bn.js": {
+          "version": "4.12.0",
+          "resolved": "https://registry.npmjs.org/bn.js/-/bn.js-4.12.0.tgz",
+          "integrity": "sha512-c98Bf3tPniI+scsdk237ku1Dc3ujXQTSgyiPUDEOe7tRkhrqridvh8klBv0HCEso1OLOYcHuCv/cS6DNxKH+ZA=="
+        },
+        "inherits": {
+          "version": "2.0.4",
+          "resolved": "https://registry.npmjs.org/inherits/-/inherits-2.0.4.tgz",
+          "integrity": "sha512-k/vGaX4/Yla3WzyMCvTQOXYeIHvqOKtnqBduzTHpzpQZzAskKMhZ2K+EnBiSM9zGSoIFeMpXKxa4dYeZIQqewQ=="
+        }
       }
     },
     "emitter-mixin": {
@@ -2478,11 +2490,6 @@
         "vary": "~1.1.2"
       }
     },
-    "extend": {
-      "version": "3.0.2",
-      "resolved": "https://registry.npmjs.org/extend/-/extend-3.0.2.tgz",
-      "integrity": "sha512-fjquC59cD7CyW6urNXK0FBufkZcoiGG80wTuPujX590cB5Ttln20E2UB4S/WARVqhXffZl2LNgS+gQdPIIim/g=="
-    },
     "extend-shallow": {
       "version": "3.0.2",
       "resolved": "https://registry.npmjs.org/extend-shallow/-/extend-shallow-3.0.2.tgz",
@@ -2761,7 +2768,8 @@
         },
         "ansi-regex": {
           "version": "2.1.1",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "aproba": {
           "version": "1.2.0",
@@ -2779,11 +2787,13 @@
         },
         "balanced-match": {
           "version": "1.0.0",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "brace-expansion": {
           "version": "1.1.11",
           "bundled": true,
+          "optional": true,
           "requires": {
             "balanced-match": "^1.0.0",
             "concat-map": "0.0.1"
@@ -2796,15 +2806,18 @@
         },
         "code-point-at": {
           "version": "1.1.0",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "concat-map": {
           "version": "0.0.1",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "console-control-strings": {
           "version": "1.1.0",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "core-util-is": {
           "version": "1.0.2",
@@ -2907,7 +2920,8 @@
         },
         "inherits": {
           "version": "2.0.3",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "ini": {
           "version": "1.3.5",
@@ -2917,6 +2931,7 @@
         "is-fullwidth-code-point": {
           "version": "1.0.0",
           "bundled": true,
+          "optional": true,
           "requires": {
             "number-is-nan": "^1.0.0"
           }
@@ -2929,17 +2944,20 @@
         "minimatch": {
           "version": "3.0.4",
           "bundled": true,
+          "optional": true,
           "requires": {
             "brace-expansion": "^1.1.7"
           }
         },
         "minimist": {
           "version": "0.0.8",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "minipass": {
           "version": "2.3.5",
           "bundled": true,
+          "optional": true,
           "requires": {
             "safe-buffer": "^5.1.2",
             "yallist": "^3.0.0"
@@ -2956,6 +2974,7 @@
         "mkdirp": {
           "version": "0.5.1",
           "bundled": true,
+          "optional": true,
           "requires": {
             "minimist": "0.0.8"
           }
@@ -3028,7 +3047,8 @@
         },
         "number-is-nan": {
           "version": "1.0.1",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "object-assign": {
           "version": "4.1.1",
@@ -3038,6 +3058,7 @@
         "once": {
           "version": "1.4.0",
           "bundled": true,
+          "optional": true,
           "requires": {
             "wrappy": "1"
           }
@@ -3113,7 +3134,8 @@
         },
         "safe-buffer": {
           "version": "5.1.2",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "safer-buffer": {
           "version": "2.1.2",
@@ -3143,6 +3165,7 @@
         "string-width": {
           "version": "1.0.2",
           "bundled": true,
+          "optional": true,
           "requires": {
             "code-point-at": "^1.0.0",
             "is-fullwidth-code-point": "^1.0.0",
@@ -3160,6 +3183,7 @@
         "strip-ansi": {
           "version": "3.0.1",
           "bundled": true,
+          "optional": true,
           "requires": {
             "ansi-regex": "^2.0.0"
           }
@@ -3198,11 +3222,13 @@
         },
         "wrappy": {
           "version": "1.0.2",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "yallist": {
           "version": "3.0.3",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         }
       }
     },
@@ -4678,16 +4704,6 @@
         }
       }
     },
-    "postcss-css-variables": {
-      "version": "0.12.0",
-      "resolved": "https://registry.npmjs.org/postcss-css-variables/-/postcss-css-variables-0.12.0.tgz",
-      "integrity": "sha512-fSgIfR+g/kZ2GeV3GH7wyNslDi7KH/Z+zwtHdEcmHv86mu+o71va9r9rqFLPR0VKi2BzoQZbCyw89oXK/XevIQ==",
-      "requires": {
-        "escape-string-regexp": "^1.0.3",
-        "extend": "^3.0.1",
-        "postcss": "^6.0.8"
-      }
-    },
     "postcss-load-config": {
       "version": "2.0.0",
       "resolved": "https://registry.npmjs.org/postcss-load-config/-/postcss-load-config-2.0.0.tgz",