Revert timers-browserify to 1.x

Reducing the global polyfill for setImmediate broke tests in webpack because webpack tries to shim the polyfill itself.

Author: jhnns

package.json

@@ -26,7 +26,7 @@
     "stream-browserify": "^2.0.1",
     "stream-http": "^2.3.1",
     "string_decoder": "^0.10.25",
-    "timers-browserify": "^2.0.2",
+    "timers-browserify": "^1.4.2",
     "tty-browserify": "0.0.0",
     "url": "^0.11.0",
     "util": "^0.10.3",