Bump omniauth from 2.0.4 to 2.1.0

Bumps [omniauth](https://github.com/omniauth/omniauth) from 2.0.4 to 2.1.0.
- [Release notes](https://github.com/omniauth/omniauth/releases)
- [Commits](https://github.com/omniauth/omniauth/compare/v2.0.4...v2.1.0)

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

Signed-off-by: dependabot[bot] <support@github.com>

Gemfile

@@ -36,7 +36,7 @@ gem "jquery-rails", "~> 4.5.0"
 gem "jquery-ui-rails", "~> 6.0.1"
 gem "kaminari", "~> 1.2.2"
 gem "mini_magick", "~> 4.11.0"
-gem "omniauth", "~> 2.0.4"
+gem "omniauth", "~> 2.1.0"
 gem "omniauth-facebook", "~> 8.0.0"
 gem "omniauth-google-oauth2", "~> 1.0.0"
 gem "omniauth-rails_csrf_protection", "~> 1.0.1"

Gemfile.lock

@@ -416,9 +416,9 @@ GEM
     octokit (4.21.0)
       faraday (>= 0.9)
       sawyer (~> 0.8.0, >= 0.5.3)
-    omniauth (2.0.4)
+    omniauth (2.1.0)
       hashie (>= 3.4.6)
-      rack (>= 1.6.2, < 3)
+      rack (>= 2.2.3)
       rack-protection
     omniauth-facebook (8.0.0)
       omniauth-oauth2 (~> 1.2)
@@ -758,7 +758,7 @@ DEPENDENCIES
   letter_opener_web (~> 2.0.0)
   mdl (~> 0.11.0)
   mini_magick (~> 4.11.0)
-  omniauth (~> 2.0.4)
+  omniauth (~> 2.1.0)
   omniauth-facebook (~> 8.0.0)
   omniauth-google-oauth2 (~> 1.0.0)
   omniauth-rails_csrf_protection (~> 1.0.1)