chore(package): update steal to version 2.1.5

Closes #44

Author: greenkeeper[bot]

package.json

@@ -52,7 +52,7 @@
     "can-make-map": "^1.0.0",
     "detect-cyclic-packages": "^1.1.0",
     "jshint": "^2.9.1",
-    "steal": "^1.11.8",
+    "steal": "^2.1.5",
     "steal-qunit": "^1.0.1",
     "steal-tools": "^1.11.9",
     "testee": "^0.8.0"