Bump factory_girl_rails from 4.5.0 to 4.9.0

Bumps [factory_girl_rails](https://github.com/thoughtbot/factory_girl_rails) from 4.5.0 to 4.9.0.
- [Changelog](https://github.com/thoughtbot/factory_bot_rails/blob/master/NEWS)
- [Commits](thoughtbot/factory_bot_rails@v4.5.0...v4.9.0)

Gemfile.lock

@@ -120,10 +120,10 @@ GEM
     erubis (2.7.0)
     excon (0.71.1)
     execjs (2.6.0)
-    factory_girl (4.5.0)
+    factory_girl (4.9.0)
       activesupport (>= 3.0.0)
-    factory_girl_rails (4.5.0)
-      factory_girl (~> 4.5.0)
+    factory_girl_rails (4.9.0)
+      factory_girl (~> 4.9.0)
       railties (>= 3.0.0)
     faraday (0.9.1)
       multipart-post (>= 1.2, < 3)