Remove unused gems

Gemfile

@@ -18,8 +18,6 @@ gem 'pg', '~> 0.18.2', group: :postgres
 gem 'rugged', '~> 0.25.1.1'
 
 gem 'faraday', '~> 0.11.0'
-gem 'net-http-persistent', '~> 2.9.4'
-gem 'faraday-http-cache'
 
 # Authentication libraries
 gem 'devise', '~> 4.2'

Gemfile.lock

@@ -195,8 +195,6 @@ GEM
       railties (>= 3.0.0)
     faraday (0.11.0)
       multipart-post (>= 1.2, < 3)
-    faraday-http-cache (2.0.0)
-      faraday (~> 0.8)
     faraday_middleware (0.11.0.1)
       faraday (>= 0.7.4, < 1.0)
     faraday_middleware-multi_json (0.0.6)
@@ -449,7 +447,6 @@ GEM
     mustermann-grape (0.4.0)
       mustermann (= 0.4.0)
     mysql2 (0.3.20)
-    net-http-persistent (2.9.4)
     net-ldap (0.12.1)
     net-ssh (3.0.1)
     netrc (0.11.0)
@@ -895,7 +892,6 @@ DEPENDENCIES
   email_spec (~> 1.6.0)
   factory_girl_rails (~> 4.7.0)
   faraday (~> 0.11.0)
-  faraday-http-cache
   ffaker (~> 2.4)
   flay (~> 2.8.0)
   fog-aws (~> 0.9)
@@ -946,7 +942,6 @@ DEPENDENCIES
   minitest (~> 5.7.0)
   mousetrap-rails (~> 1.4.6)
   mysql2 (~> 0.3.16)
-  net-http-persistent (~> 2.9.4)
   net-ssh (~> 3.0.1)
   nokogiri (~> 1.6.7, >= 1.6.7.2)
   oauth2 (~> 1.3.0)