Install golang 1.8 on skia-ct-master
Install golang 1.8 on skia-ct-master

BUG=skia:6700

Change-Id: Idb0e35b68616be8d2b5d941af47da157f1d5785b
Reviewed-on: https://skia-review.googlesource.com/18139
Reviewed-by: Ben Wagner <3ef7217be91069877d94f7907ce5479000772cd3@google.com>

google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot