Restful refactor of accounts/ routes (#2133)

* Add routing specs for accounts followers and following actions

* Use more restful route naming for public account follow pages

Moves two actions:
- accounts#followers to accounts/follower_accounts#index
- accounts#following to accounts/following_accounts#index

Adds routing spec to ensure prior URLs are preserved.

spec/controllers/account_unfollow_controller_spec.rb

@@ -0,0 +1,24 @@
+require 'rails_helper'
+
+describe AccountUnfollowController do
+  render_views
+  let(:user) { Fabricate(:user) }
+  let(:alice) { Fabricate(:account, username: 'alice') }
+
+  describe 'POST #create' do
+    before do
+      sign_in(user)
+    end
+
+    it 'redirects to account path' do
+      service = double
+      allow(UnfollowService).to receive(:new).and_return(service)
+      allow(service).to receive(:call)
+
+      post :create, params: { account_username: alice.username }
+
+      expect(service).to have_received(:call).with(user.account, alice)
+      expect(response).to redirect_to(account_path(alice))
+    end
+  end
+end