Rename gitlab's identifier for consistency's sake

I was going through our other test reporters to add gitlab CI support
and noticed that ruby and python already have it, and identify it as
"gitlab-ci". Seems best to identify it in the same way here.

Author: maxjacobson

src/TestReporter/Entity/CiInfo.php

@@ -188,7 +188,7 @@ protected function werckerProperties(array $server)
     protected function gitlabCiProperties(array $server)
     {
         return array(
-            "name"             => "gitlabci",
+            "name"             => "gitlab-ci",
             "build_identifier" => $server["CI_BUILD_ID"],
             "branch"           => $server["CI_BUILD_REF_NAME"],
             "commit_sha"       => $server["CI_BUILD_REF"],

tests/Unit/TestReporter/Entity/CiInfoTest.php

@@ -214,7 +214,7 @@ public function testToArrayReturnsGitlabCiProperties()
         $info = new CiInfo($server);
 
         $expected = array(
-            'name' => 'gitlabci',
+            'name' => 'gitlab-ci',
             'build_identifier' => $buildIdentifier,
             'branch' => $branch,
             'commit_sha' => $commitSha,