Make GithubPullRequest able to handle error status

lib/cc/services/github_pull_requests.rb

@@ -63,6 +63,12 @@ def receive_pull_request
     when "success"
       add_comment
       update_status("success", "Code Climate has analyzed this pull request.")
+    when "error"
+      update_status(
+        "error",
+        "Code Climate encountered an error while attempting to analyze this " +
+          "pull request."
+      )
     end
   end
 

test/github_pull_requests_test.rb

@@ -27,6 +27,20 @@ def test_pull_request_status_success
     })
   end
 
+  def test_pull_request_status_error
+    expect_status_update("pbrisbin/foo", "abc123", {
+      "state"       => "error",
+      "description" => /encountered an error/,
+    })
+
+    receive_pull_request({ update_status: true }, {
+      github_slug: "pbrisbin/foo",
+      commit_sha:  "abc123",
+      state:       "error",
+    })
+
+  end
+
   def test_pull_request_status_test_success
     @stubs.post("/repos/pbrisbin/foo/statuses/#{"0" * 40}") { |env| [422, {}, ""] }