added dumb tests for parity and ethcore-rpc to include them in coverage reports, added TARGETS env variable to travis.yml

parity/main.rs

@@ -169,3 +169,7 @@ impl IoHandler<NetSyncMessage> for ClientIoHandler {
 	}
 }
 
+/// Parity needs at least 1 test to generate coverage reports correctly.
+#[test]
+fn if_works() {
+}