Add go wrapper, streamline java decoder: (#524)

* add (c)brotli golang wrapper
 * remove (language-specific) enums in java decoder
diff --git a/WORKSPACE b/WORKSPACE
index 9771d45..4c3c9b7 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -7,3 +7,12 @@
     name = "junit_junit",
     artifact = "junit:junit:4.12",
 )
+
+git_repository(
+    name = "io_bazel_rules_go",
+    remote = "https://github.com/bazelbuild/rules_go.git",
+    tag = "0.4.1",
+)
+load("@io_bazel_rules_go//go:def.bzl", "go_repositories")
+
+go_repositories()