chore: clean up old code

- removed jest config from package.json
- added cov to npm clean script
- added tests to .npmignore

.npmignore

@@ -1,6 +1,6 @@
 .DS_Store
 *.log
 src
-test
+tests
 examples
 coverage

package.json

@@ -5,7 +5,7 @@
   "main": "lib/react-scale-text.js",
   "module": "lib/index.js",
   "scripts": {
-    "clean": "rimraf lib coverage",
+    "clean": "rimraf lib coverage cov",
     "build": "babel src --out-dir lib --ignore __tests__,__mocks__ && npm run build:umd",
     "build:umd": "webpack && NODE_ENV=production webpack",
     "build:analyze": "webpack --json > ./lib/build-stats.json",
@@ -85,17 +85,5 @@
     "lodash": "^4.17.4",
     "warning": "^3.0.0",
     "shortid": "^2.2.8"
-  },
-  "jest": {
-    "testEnvironment": "jsdom",
-    "snapshotSerializers": [
-      "enzyme-to-json/serializer"
-    ],
-    "unmockedModulePathPatterns": [
-      "react",
-      "react-dom",
-      "react-addons-test-utils",
-      "enzyme"
-    ]
   }
 }