Add approve_user method

lib/gitlab/client/users.rb

@@ -110,6 +110,17 @@ def unblock_user(user_id)
       post("/users/#{user_id}/unblock")
     end
 
+    # Approves the specified user. Available only for admin.
+    #
+    # @example
+    #   Gitlab.approve_user(15)
+    #
+    # @param [Integer] user_id The Id of user
+    # @return [Boolean] success or not
+    def approve_user(user_id)
+      post("/users/#{user_id}/approve")
+    end
+
     # Creates a new user session.
     #
     # @example

spec/fixtures/user_approve.json

@@ -0,0 +1 @@
+true

spec/gitlab/client/users_spec.rb

@@ -170,6 +170,21 @@
     end
   end
 
+  describe '.approve_user' do
+    before do
+      stub_post('/users/1/approve', 'user_approve')
+      @result = Gitlab.approve_user(1)
+    end
+
+    it 'gets the correct resource' do
+      expect(a_post('/users/1/approve')).to have_been_made
+    end
+
+    it 'returns boolean' do
+      expect(@result).to eq(true)
+    end
+  end
+
   describe '.session' do
     after do
       Gitlab.endpoint = 'https://api.example.com'