deps: update jest (#196)

Seems to not make all the tests fail 😆

Fixes: #195

Author: koddsson

package.json

@@ -43,7 +43,7 @@
     "eslint-plugin-prettier": "^2.0.1",
     "glob": "^7.0.3",
     "isomorphic-fetch": "^2.2.1",
-    "jest": "^19.0.2",
+    "jest": "^20.0.3",
     "jest-fetch-mock": "^1.0.8",
     "js-beautify": "^1.6.12",
     "jsdom": "^9.11.0",