allow manual initialization and config as an arg

package.json

@@ -43,7 +43,6 @@
     "setupFiles": [
       "./setupTests.js"
     ],
-    "mapCoverage": true,
     "coverageReporters": [
       "lcov"
     ],
@@ -77,7 +76,7 @@
     "babel": "^6.5.2",
     "babel-cli": "^6.18.0",
     "babel-core": "^6.23.1",
-    "babel-jest": "^21.2.0",
+    "babel-jest": "^22.0.0",
     "babel-loader": "^7.0.0",
     "babel-plugin-lodash": "^3.2.0",
     "babel-plugin-module-resolver": "^3.0.0",
@@ -104,8 +103,8 @@
     "file-loader": "^1.1.4",
     "identity-obj-proxy": "^3.0.0",
     "imports-loader": "^0.7.1",
-    "jest": "^21.2.1",
-    "jest-cli": "^21.2.1",
+    "jest": "^22.0.0",
+    "jest-cli": "^22.0.0",
     "lint-staged": "^3.3.1",
     "npm-check": "^5.2.3",
     "postcss-cssnext": "^3.0.2",