Support new Go releases (bazel-contrib#2028)

Support for Go 1.12.3, 1.12.4, 1.11.8, and 1.11.9.

Also, re-enable testing on ubuntu1404 in CI.

Support new Go releases (bazel-contrib#2028)

Support for Go 1.12.3, 1.12.4, 1.11.8, and 1.11.9.

Also, re-enable testing on ubuntu1404 in CI.

Support new Go releases (bazel-contrib#2028)

Support for Go 1.12.3, 1.12.4, 1.11.8, and 1.11.9.

Also, re-enable testing on ubuntu1404 in CI.

Support Go 1.12.2 and 1.11.7 (bazel-contrib#2022)

Also, drop ubuntu1404 from CI (hopefully temporarily?)

Support Go 1.12.2 and 1.11.7 (bazel-contrib#2022)

Also, drop ubuntu1404 from CI (hopefully temporarily?)

Support Go 1.12.2 and 1.11.7 (bazel-contrib#2022)

Also, drop ubuntu1404 from CI (hopefully temporarily?)

Add support for Go 1.12.1 and 1.11.6 (bazel-contrib#1994)

Add support for Go 1.12.1 and 1.11.6 (bazel-contrib#1994)

Add support for Go 1.12.1 and 1.11.6 (bazel-contrib#1994)

Remove deprecated support for Go 1.9 and go_vet_test (bazel-contrib#1977

)