Remove SignatureTest from known failures now that it passes.

bug:17894722
Change-Id: I4cd4f1c17f9d50e06d1515aaa4e621d0c1b75a94
diff --git a/tests/expectations/knownfailures.txt b/tests/expectations/knownfailures.txt
index ae78695..5922273 100644
--- a/tests/expectations/knownfailures.txt
+++ b/tests/expectations/knownfailures.txt
@@ -8,13 +8,6 @@
   bug: 17595050
 },
 {
-  description: "signature test stil needs more work",
-  names: [
-    "android.signature.cts.SignatureTest#testSignature"
-  ],
-  bug: 17894722
-},
-{
   description: "Not all jdwp features are currently supported. These tests will fail",
   names: [
     "org.apache.harmony.jpda.tests.jdwp.DebuggerOnDemand.OnthrowDebuggerLaunchTest#testDebuggerLaunch001",