Bug 1369908 - Schedule linux64-ccov, and linux64-jsdcov on all mozilla-central pushes. r=jmaher

This patch removes the nightly code coverage run in favor of simply running the two code coverage builds on every single push to mozilla-central for a more granular view of code coverage over time.

MozReview-Commit-ID: E4Xp5bB19m9

taskcluster/taskgraph/transforms/tests.py

@@ -514,9 +514,9 @@ def enable_code_coverage(config, tests):
             test['mozharness'].setdefault('extra-options', []).append('--code-coverage')
             test['when'] = {}
             test['instance-size'] = 'xlarge'
-            test['run-on-projects'] = []
+            test['run-on-projects'] = ['mozilla-central']
         elif test['build-platform'] == 'linux64-jsdcov/opt':
-            test['run-on-projects'] = []
+            test['run-on-projects'] = ['mozilla-central']
         yield test