Bump pygments from 2.3.1 to 2.7.4 in /requirements

Bumps [pygments](https://github.com/pygments/pygments) from 2.3.1 to 2.7.4.
- [Release notes](https://github.com/pygments/pygments/releases)
- [Changelog](https://github.com/pygments/pygments/blob/master/CHANGES)
- [Commits](pygments/pygments@2.3.1...2.7.4)

Signed-off-by: dependabot[bot] <[email protected]>

requirements/documentation.txt

@@ -1,20 +1,20 @@
 alabaster==0.7.12
-Babel==2.6.0
+babel==2.6.0
 certifi==2018.11.29
 chardet==3.0.4
 docutils==0.14
 idna==2.5
 imagesize==1.1.0
-Jinja2==2.10
-MarkupSafe==1.1.1
+jinja2==2.10
+markupsafe==1.1.1
 packaging==19.0
-Pygments==2.3.1
+pygments==2.7.4
 pyparsing==2.3.1
 pytz==2018.9
 requests==2.21.0
 six==1.12.0
 snowballstemmer==1.2.1
-Sphinx==1.8.4
 sphinx-rtd-theme==0.4.3
+sphinx==1.8.4
 sphinxcontrib-websupport==1.1.0
-urllib3==1.24.1
+urllib3==1.24.3

requirements/system_tests.txt

@@ -19,7 +19,7 @@ attrs==20.3.0
     #   twisted
 autobahn[asyncio,compress,encryption,scram,serialization,twisted]==21.3.1
     # via
-    #   -c requirements/constraints.txt
+    #   -c constraints.txt
     #   crossbar
 automat==20.2.0
     # via
@@ -39,7 +39,7 @@ cbor==1.0.0
     #   crossbar
 certifi==2018.11.29
     # via
-    #   -c requirements/constraints.txt
+    #   -c constraints.txt
     #   requests
 cffi==1.14.5
     # via
@@ -51,7 +51,7 @@ cffi==1.14.5
     #   zlmdb
 chardet==3.0.4
     # via
-    #   -c requirements/constraints.txt
+    #   -c constraints.txt
     #   requests
 click==7.1.2
     # via
@@ -66,7 +66,7 @@ constantly==15.1.0
 coverage==5.5
     # via pytest-cov
 crossbar==21.3.1
-    # via -r requirements/system_tests.in
+    # via -r system_tests.in
 cryptography==3.4.7
     # via
     #   autobahn
@@ -93,7 +93,7 @@ hyperlink==21.0.0
     #   twisted
 idna==2.5
     # via
-    #   -c requirements/constraints.txt
+    #   -c constraints.txt
     #   crossbar
     #   hyperlink
     #   requests
@@ -155,7 +155,7 @@ pyasn1==0.4.8
     #   service-identity
 pycparser==2.20
     # via cffi
-pygments==2.8.1
+pygments==2.7.4
     # via crossbar
 pynacl==1.4.0
     # via
@@ -174,19 +174,19 @@ pyqrcode==1.2.1
     #   autobahn
     #   crossbar
 pytest-cov==2.11.1
-    # via -r requirements/system_tests.in
+    # via -r system_tests.in
 pytest-forked==1.3.0
     # via pytest-xdist
 pytest-xdist==2.2.1
-    # via -r requirements/system_tests.in
+    # via -r system_tests.in
 pytest==6.2.3
     # via
-    #   -r requirements/system_tests.in
+    #   -r system_tests.in
     #   pytest-cov
     #   pytest-forked
     #   pytest-xdist
 python-dotenv==0.17.0
-    # via -r requirements/system_tests.in
+    # via -r system_tests.in
 python-snappy==0.6.0
     # via autobahn
 pytrie==0.4.0
@@ -195,12 +195,12 @@ pytrie==0.4.0
     #   crossbar
 pyyaml==5.4.1
     # via
-    #   -r requirements/system_tests.in
+    #   -r system_tests.in
     #   crossbar
     #   zlmdb
 requests==2.25.1
     # via
-    #   -r requirements/system_tests.in
+    #   -r system_tests.in
     #   treq
 sdnotify==0.3.2
     # via crossbar
@@ -227,7 +227,7 @@ treq==21.1.0
     # via crossbar
 twisted[tls]==21.2.0
     # via
-    #   -c requirements/constraints.txt
+    #   -c constraints.txt
     #   autobahn
     #   treq
     #   txtorcon
@@ -244,7 +244,7 @@ ujson==4.0.2
     # via autobahn
 urllib3==1.24.3
     # via
-    #   -c requirements/constraints.txt
+    #   -c constraints.txt
     #   crossbar
     #   requests
 watchdog==2.0.3