Remove gwt-test-utils and disabled tests that depend on it

gwt-test-utils is broken [1] and the tests that depend on it have
been disabled for ages.

It doesn't look like there's going to be any new release of a
fixed version, and since Gerrit is moving away from GWT it's not
worth trying to maintain it ourselves.

Remove the disabled tests, and the dependency to gwt-test-utils.

[1] https://github.com/gwt-test-utils/gwt-test-utils/issues/68

Change-Id: If7ae8d5790146ddfad528a1db2f6f6c3ae497970

lib/gwt/BUCK

@@ -28,22 +28,3 @@ maven_jar(
   visibility = ['PUBLIC'],
 )
 
-maven_jar(
-  name = 'gwt-test-utils',
-  id = 'com.googlecode.gwt-test-utils:gwt-test-utils:0.47',
-  sha1 = '284749ed37d8034bac05e374070c09cce88db540',
-  license = 'Apache2.0',
-  deps = [
-    ':javassist',
-    '//lib/log:api',
-  ],
-  visibility = ['PUBLIC'],
-)
-
-maven_jar(
-  name = 'javassist',
-  id = 'org.javassist:javassist:3.18.1-GA',
-  sha1 = 'd9a09f7732226af26bf99f19e2cffe0ae219db5b',
-  license = 'Apache2.0',
-  visibility = ['PUBLIC'],
-)