Merge branch 'develop' into greenkeeper/jest-21.0.0

Author: buehler

package.json

@@ -31,7 +31,7 @@
     "@types/jest": "^20.0.5",
     "del-cli": "^1.1.0",
     "jest": "^21.0.0",
-    "ts-jest": "^20.0.7",
+    "ts-jest": "^21.0.0",
     "tslint": "^5.5.0",
     "tslint-config-airbnb": "^5.2.1",
     "tsutils": "^2.8.0",