Fixes#2207. This is actually a workaround. Ideally users shouldn't need
to -keep classes, but it's a bit risky to fix the real issue before 1.1.
The further fix will be done as part of #2633.
The interop app's build.gradle change is necessary to compile with newer
Gradle versions. The com.google.errorprone.annotations was necessary in
order to prevent annotation warnings from failing the build.
Also removed warnings about protoc version matching runtime, since this
is no longer supposed to be a problem (starting with 3.0.0-beta-4) and
all our tests ran fine when using protoc 3.0.2 with protobuf runtime
3.1.0.
Fixes#2316
protoc no longer builds in 3.0.0 because auto-download of the gmock zip
now fails. 3.0.2 has a fix to autogen:
bba446bbf2
All that was strictly necessary was to update .travis.yml and
buildscripts/, but it helps our sanity to keep the rest of the protobuf
versions in sync. Lite is left on its existing version, because it did
not see a bump of neither the java library nor the protoc plugin.
Eric Anderson
Carl Mastrangelo
Kun Zhang
Xiao Hang