* Break circular dependency between core and util
Created a new :common project and moved a minimum
number of classes to break the circular dependency
between the two projects. This gets rid of the
gradle lint dependency warnings.
Also separated api classes and testing helpers into
separate source sets in :common so that testing
classes may be restricted to test configurations.
* Upgrade to Truth 1.0
Refactored fail(...) to assertWithMessage().fail().
Upgraded com.google.monitoring-client family of dependencies to 1.0.6
Also fixed bad use of io.StringIO (on binary buffer) recently introduced to
google-java-format-diff.py.
* Fix dependency-locking config
Reenable dependency locking after a bug errorneouly turned it off.
Removed the guava-related workaround that forcefully resolve to
the -jre distribution.
Enabled locking for buildSrc by updating its property file.
Updated all lock files.
