fix gemfile

Gemfile.lock

@@ -253,7 +253,7 @@ GEM
     fog-xml (0.1.2)
       fog-core
       nokogiri (~> 1.5, >= 1.5.11)
-    font-awesome-rails (4.5.0.1)
+    font-awesome-rails (4.6.1.0)
       railties (>= 3.2, < 5.1)
     foreman (0.78.0)
       thor (~> 0.19.1)
@@ -881,7 +881,7 @@ DEPENDENCIES
   fog-google (~> 0.3)
   fog-local (~> 0.3)
   fog-openstack (~> 0.1)
-  font-awesome-rails (~> 4.2)
+  font-awesome-rails (~> 4.6.1)
   foreman
   fuubar (~> 2.0.0)
   gemnasium-gitlab-service (~> 0.2)