chore(package): update steal to version 2.1.7

Closes #54

Author: greenkeeper[bot]

package.json

@@ -21,7 +21,7 @@
     "fixpack": "^2.3.1",
     "jquery": "^3.2.1",
     "jshint": "^2.9.1",
-    "steal": "^1.3.1",
+    "steal": "^2.1.7",
     "steal-qunit": "^1.0.1",
     "steal-tools": "^1.2.0",
     "testee": "^0.8.0"