Simplify Travis-CI build: check only select

Change-Id: If42b051e5c9109ba75abfa5a9236c32b677f3ddb
Reviewed-on: http://review.couchbase.org/28448
Reviewed-by: Sergey Avseyev <sergey.avseyev@gmail.com>
Tested-by: Sergey Avseyev <sergey.avseyev@gmail.com>