chore(package): update sinon-chai to version 3.2.0

Closes #33

Author: greenkeeper[bot]

package.json

@@ -36,6 +36,6 @@
     "proxyquire": "^1.7.10",
     "rimraf": "^2.5.4",
     "sinon": "^1.17.6",
-    "sinon-chai": "^2.8.0"
+    "sinon-chai": "^3.2.0"
   }
 }