chore(build): add coverall integration

Author: tusharmath

package.json

@@ -3,20 +3,22 @@
   "description": "Observables for the calorie conscious",
   "main": "src/Observable",
   "scripts": {
-    "test": "ava",
+    "benchmark": "date >> benchmark.md && node chore/benchmark >> benchmark.md",
     "cleanup": "rm -rf ./src/**/*.js && rm -rf ./src/**/*.map",
-    "lint": "tslint ./src/**.ts",
+    "coverage": "nyc npm test && nyc report --reporter=text-lcov | coveralls",
     "hydra": "node --trace-hydrogen --trace-phase=Z --trace-deopt --code-comments --hydrogen-track-positions --redirect-code-traces --redirect-code-traces-to=code.asm chore/benchmark.js",
-    "rfc": "node chore/rfc",
-    "benchmark": "date >> benchmark.md && node chore/benchmark >> benchmark.md",
+    "lint": "tslint ./src/**.ts",
     "postinstall": "tsc",
-    "semantic-release": "semantic-release pre && npm publish && semantic-release post"
+    "rfc": "node chore/rfc",
+    "semantic-release": "semantic-release pre && npm publish && semantic-release post",
+    "test": "ava"
   },
   "author": "",
   "license": "ISC",
   "devDependencies": {
     "ava": "^0.16.0",
     "benchmark": "^2.1.1",
+    "coveralls": "^2.11.14",
     "cz-conventional-changelog": "^1.2.0",
     "es-observable-tests": "^0.3.0",
     "ghooks": "^1.3.2",