travis: set up coveralls coverage

.travis.yml

@@ -1,7 +1,13 @@
 language: node_js
 node_js:
-  - "0.10"
-  - "0.11"
+- '0.10'
+- '0.11'
 branches:
   only:
-    - master
+  - master
+env:
+  global:
+    secure: ewqsRnX7z3+g6q+mM6peRPhuTlTlkJIRmVG/Ya9AcDXEb7as49KDTdqfMcOu7+FxF50ehqla+TRRCLRPOcVkWqs72OVUXEsjRASp9jQwpQGl+g/vZhyTMwlM2ENEkyiFQtobI1hYKgVW1ogftkc6vm7ywvoyTrFp/leVJBrTuHk=
+script:
+- npm test --coverage
+- npm run-script coveralls

package.json

@@ -4,7 +4,8 @@
   "description": "EC cryptography",
   "main": "lib/elliptic.js",
   "scripts": {
-    "test": "make lint && istanbul test _mocha --reporter=spec test/*-test.js"
+    "test": "make lint && istanbul test _mocha --reporter=spec test/*-test.js",
+    "coveralls": "cat ./coverage/lcov.info | coveralls"
   },
   "repository": {
     "type": "git",
@@ -24,6 +25,7 @@
   "homepage": "https://github.com/indutny/elliptic",
   "devDependencies": {
     "browserify": "^3.44.2",
+    "coveralls": "^2.11.3",
     "istanbul": "^0.3.17",
     "jscs": "^1.11.3",
     "jshint": "^2.6.0",