Change from istanbul to nyc (#103)

* Change from istanbul to nyc

* Latest version of nyc

Author: eddiemoore

.gitignore

@@ -12,6 +12,7 @@ lib-cov
 
 # Coverage directory used by tools like istanbul
 coverage
+.nyc_output
 
 # Grunt intermediate storage (http://gruntjs.com/creating-plugins#storing-task-files)
 .grunt

.travis.yml

@@ -12,4 +12,4 @@ node_js:
   - "4"
 
 after_success:
-  - ./bin/codecov -e TRAVIS_NODE_VERSION -f coverage/coverage.json
+  - ./bin/codecov -e TRAVIS_NODE_VERSION -f .nyc_output/*.json