Reinstate targets that no longer fail tests

This change reinstates targets that were marked as KTF over the past year, but are now succeeding.

Differential Revision: https://phabricator.twitter.biz/D1214058

Author: jdm-twtr

finagle-memcached/src/test/scala/BUILD

@@ -25,10 +25,7 @@ junit_tests(
     sources = ["**/*.scala"] + exclude_globs(EXTERNAL_SOURCES),
     compiler_option_sets = ["fatal_warnings"],
     platform = "java8",
-    tags = [
-        "bazel-compatible",
-        "known-to-fail-jira:CSL-12419",
-    ],
+    tags = ["bazel-compatible"],
     dependencies = [
         ":external",
         "3rdparty/jvm/com/fasterxml/jackson/core:jackson-databind",