Update gitlab_git to version 2.3.1

Gemfile

@@ -23,7 +23,7 @@ gem 'omniauth-github'
 # Extracting information from a git repository
 # Provide access to Gitlab::Git library
-gem "gitlab_git", '2.2.0'
+gem "gitlab_git", '2.3.1'
 # Ruby/Rack Git Smart-HTTP Server Handler
 gem 'gitlab-grack', '~> 1.0.1', require: 'grack'

Gemfile.lock

@@ -179,7 +179,7 @@ GEM
     gitlab-pygments.rb (0.3.2)
       posix-spawn (~> 0.3.6)
       yajl-ruby (~> 1.1.0)
-    gitlab_git (2.2.0)
+    gitlab_git (2.3.1)
       activesupport (~> 3.2.13)
       github-linguist (~> 2.3.4)
       gitlab-grit (~> 2.6.0)
@@ -421,7 +421,7 @@ GEM
       rspec-expectations (~> 2.13.0)
       rspec-mocks (~> 2.13.0)
     ruby-hmac (0.4.0)
-    ruby-progressbar (1.1.1)
+    ruby-progressbar (1.2.0)
     rubyntlm (0.1.1)
     rubyzip (0.9.9)
     safe_yaml (0.9.3)
@@ -572,7 +572,7 @@ DEPENDENCIES
   gitlab-gollum-lib (~> 1.0.1)
   gitlab-grack (~> 1.0.1)
   gitlab-pygments.rb (~> 0.3.2)
-  gitlab_git (= 2.2.0)
+  gitlab_git (= 2.3.1)
   gitlab_meta (= 6.0)
   gitlab_omniauth-ldap (= 1.0.3)
   gon