hard-code istanbul version.

Author: beefancohen

package.json

@@ -32,7 +32,7 @@
     "babel-preset-es2015": "^6.6.0",
     "coveralls": "^2.11.8",
     "eslint": "^2.2.0",
-    "istanbul": "^1.0.0-alpha.2r",
+    "istanbul": "1.0.0-alpha.2r",
     "mocha": "^2.4.5",
     "webpack": "^1.12.14"
   },