Merge branch 'stable-2.15'
* stable-2.15:
Update bazlets to the latest stable-2.15 to use 2.15.2 API
Upgrade JGit to 4.9.2.201712150930-r.15-g5fe8e31d4
Update bazlets to latest revision on stable-2.15
Update bazlets to latest revision on stable-2.14
Format Java files with google-java-format 1.5
Update bazlets to use 2.15 release API
Add support for "expires_in" field in authentication response
Update bazlets to the latest on stable-2.14 to use 2.14.7 release API
Replace joda-time with Java 8 API
Format BUILD file with buildifier
Replace Guava's Optional with Java 8 Optional
LfsSshAuth: Check number of arguments to git-lfs-authenticate command
Change-Id: I99b4fc74e0970ff7ac217c3b58961fcd34c4f679
