Prepare for API v1 (PR #570)

Gemfile.lock

@@ -148,6 +148,9 @@ GEM
     diff-lcs (1.3)
     diffy (3.2.1)
     docile (1.3.1)
+    doorkeeper (5.0.1)
+      railties (>= 4.2)
+    doorkeeper-i18n (4.0.0)
     email_reply_trimmer (0.1.12)
     erubi (1.7.1)
     erubis (2.7.0)
@@ -284,6 +287,7 @@ GEM
     rack (1.6.10)
     rack-contrib (1.8.0)
       rack (~> 1.4)
+    rack-cors (1.0.2)
     rack-protection (1.5.5)
       rack
     rack-test (0.6.3)
@@ -498,6 +502,8 @@ DEPENDENCIES
   daemons
   database_cleaner
   date_time_attribute
+  doorkeeper
+  doorkeeper-i18n
   exception_notification
   factory_bot_rails
   faker
@@ -526,6 +532,7 @@ DEPENDENCIES
   pry-rescue
   pry-stack_explorer
   quiet_assets
+  rack-cors
   rails (~> 4.2)
   rails-assets-listjs (= 0.2.0.beta.4)
   rails-i18n