[RN] Disable TimersTest - sporadic failures on Travis

Summary:
Can't get any local failures to trigger.  Travis failure:

https://travis-ci.org/facebook/react-native/jobs/78064148

Examples/UIExplorer/UIExplorerIntegrationTests/IntegrationTests.m

@@ -57,7 +57,7 @@
   expectErrorRegex:@"because shouldThrow"];
 }
 
-- (void)testTimers
+- (void)DISABLED_testTimers // #8192477
 {
   [_runner runTest:_cmd module:@"TimersTest"];
 }