fix(Clock): Ensure that uninstalling the clock also stops auto tick

The autotick feature mistakenly does not account for the clock being a
singleton and the re-installation of the clock causes the auto ticking
exit conditions to become true again, before it has a chance to break.

src/core/Clock.js

@@ -69,6 +69,10 @@ getJasmineRequireObj().Clock = function() {
      * @function
      */
     this.uninstall = function() {
+      // Ensure auto ticking loop is aborted when clock is uninstalled
+      if (tickMode.mode === 'auto') {
+        tickMode = { mode: 'manual', counter: tickMode.counter + 1 };
+      }
       delayedFunctionScheduler = null;
       mockDate.uninstall();
       replace(global, realTimingFunctions);