Bump mongo from 2.8.0 to 2.16.4

Bumps [mongo](https://github.com/mongodb/mongo-ruby-driver) from 2.8.0 to 2.16.4.
- [Release notes](https://github.com/mongodb/mongo-ruby-driver/releases)
- [Changelog](https://github.com/mongodb/mongo-ruby-driver/blob/master/docs/release-notes.txt)
- [Commits](mongodb/mongo-ruby-driver@v2.8.0...v2.16.4)

---
updated-dependencies:
- dependency-name: mongo
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Gemfile

@@ -7,7 +7,7 @@ gem 'geocoder'
 gem 'grape'
 gem 'grape-entity'
 gem 'iso_country_codes'
-gem 'mongo', '~> 2.8.0'
+gem 'mongo', '~> 2.16.4'
 gem 'mongoid', '~> 6.0'
 gem 'rake'
 gem 'require_all'

Gemfile.lock

@@ -10,7 +10,7 @@ GEM
       tzinfo (~> 1.1)
     ast (2.4.1)
     blockenspiel (0.5.0)
-    bson (4.10.0)
+    bson (4.12.1)
     builder (3.2.4)
     concurrent-ruby (1.1.9)
     database_cleaner (1.8.5)
@@ -63,8 +63,8 @@ GEM
       mime-types-data (~> 3.2015)
     mime-types-data (3.2020.0512)
     minitest (5.14.4)
-    mongo (2.8.0)
-      bson (>= 4.4.2, < 5.0.0)
+    mongo (2.16.4)
+      bson (>= 4.8.2, < 5.0.0)
     mongoid (6.4.5)
       activemodel (>= 5.1, < 6.0.0)
       mongo (>= 2.5.1, < 3.0.0)
@@ -156,7 +156,7 @@ DEPENDENCIES
   grape-entity
   iso_country_codes
   minitest
-  mongo (~> 2.8.0)
+  mongo (~> 2.16.4)
   mongoid (~> 6.0)
   rack-test
   rake