Use :warn instead of :error for invalid commands.

lib/gitlab_keys.rb

@@ -18,7 +18,7 @@ class GitlabKeys
     when 'add-key'; add_key
     when 'rm-key';  rm_key
     else
-      $logger.error "Attempt to execute invalid gitlab-keys command #{@command.inspect}."
+      $logger.warn "Attempt to execute invalid gitlab-keys command #{@command.inspect}."
       puts 'not allowed'
       false
     end

lib/gitlab_projects.rb

@@ -32,7 +32,7 @@ class GitlabProjects
     when 'import-project'; import_project
     when 'fork-project'; fork_project
     else
-      $logger.error "Attempt to execute invalid gitlab-projects command #{@command.inspect}."
+      $logger.warn "Attempt to execute invalid gitlab-projects command #{@command.inspect}."
       puts 'not allowed'
       false
     end

spec/gitlab_keys_spec.rb

@@ -63,10 +63,10 @@ describe GitlabKeys do
       gitlab_keys.exec
     end
 
-    it 'should log an error on unknown commands' do
+    it 'should log a warning on unknown commands' do
       gitlab_keys = build_gitlab_keys('nooope')
       gitlab_keys.stub(puts: nil)
-      $logger.should_receive(:error).with('Attempt to execute invalid gitlab-keys command "nooope".')
+      $logger.should_receive(:warn).with('Attempt to execute invalid gitlab-keys command "nooope".')
       gitlab_keys.exec
     end
   end

spec/gitlab_projects_spec.rb

@@ -180,9 +180,9 @@ describe GitlabProjects do
       gitlab_projects.exec
     end
 
-    it 'should log a message for unknown commands' do
+    it 'should log a warning for unknown commands' do
       gitlab_projects = build_gitlab_projects('hurf-durf', repo_name)
-      $logger.should_receive(:error).with('Attempt to execute invalid gitlab-projects command "hurf-durf".')
+      $logger.should_receive(:warn).with('Attempt to execute invalid gitlab-projects command "hurf-durf".')
       gitlab_projects.exec
     end
   end