Remove test coverage

Doesn't add much or tell the full story now with the integration tests

package.json

@@ -23,7 +23,6 @@
     "jsdom": "^11.11.0",
     "node-pty": "0.7.6",
     "nodemon": "1.10.2",
-    "nyc": "^11.8.0",
     "puppeteer": "^1.15.0",
     "source-map-loader": "^0.2.4",
     "ts-loader": "^4.5.0",
@@ -47,7 +46,6 @@
     "lint": "tslint 'src/**/*.ts' './demo/**/*.ts'",
     "test": "node ./bin/test.js",
     "posttest": "npm run lint",
-    "test-coverage": "nyc -x '**/*test*' npm run mocha",
     "test-api": "mocha \"**/*.api.js\"",
     "prebuild": "tsc -b ./src/tsconfig.all.json",
     "build": "tsc -b ./src/tsconfig.all.json",