Spec coverage and refactor for the api/v1/accounts controllers (#3451)

spec/routing/api_routing_spec.rb

@@ -1,6 +1,45 @@
 require 'rails_helper'
 
 describe 'API routes' do
+  describe 'Credentials routes' do
+    it 'routes to verify credentials' do
+      expect(get('/api/v1/accounts/verify_credentials')).
+        to route_to('api/v1/accounts/credentials#show')
+    end
+
+    it 'routes to update credentials' do
+      expect(patch('/api/v1/accounts/update_credentials')).
+        to route_to('api/v1/accounts/credentials#update')
+    end
+  end
+
+  describe 'Account routes' do
+    it 'routes to statuses' do
+      expect(get('/api/v1/accounts/user/statuses')).
+        to route_to('api/v1/accounts/statuses#index', account_id: 'user')
+    end
+
+    it 'routes to followers' do
+      expect(get('/api/v1/accounts/user/followers')).
+        to route_to('api/v1/accounts/follower_accounts#index', account_id: 'user')
+    end
+
+    it 'routes to following' do
+      expect(get('/api/v1/accounts/user/following')).
+        to route_to('api/v1/accounts/following_accounts#index', account_id: 'user')
+    end
+
+    it 'routes to search' do
+      expect(get('/api/v1/accounts/search')).
+        to route_to('api/v1/accounts/search#show')
+    end
+
+    it 'routes to relationships' do
+      expect(get('/api/v1/accounts/relationships')).
+        to route_to('api/v1/accounts/relationships#index')
+    end
+  end
+  
   describe 'Timeline routes' do
     it 'routes to home timeline' do
       expect(get('/api/v1/timelines/home')).