Release eclipse 1.15 version

[velo]

Seems eclipse version is hardcoded to 1.13 version
https://github.com/google/google-java-format/blob/master/eclipse_plugin/pom.xml#L25

That lead to the last two releases of eclipse plugin to be stuck at 1.13
https://github.com/google/google-java-format/releases

I diff jars included under v1.15.0 and v1.14.0 and the contents is exactly the same as v1.13

I noticed a few minor differences when formatting on eclipse (v1.13) and on command line (v1.15), so a new eclipse release is necessary

[PhilippWendler]

Also at #744

[velo]

Hi @cushon where can I find the v1.15.0 release of the plugin?

Release page still only contains v1.13

[skarpushin]

Why is this closed? Issue is still there. There is a PR #826 that can fix this.

[tbroyer]

Because that's more or less a duplicate of #744