Replace codecov.io by codecov (#23)

* Replace codecov.io by codecov

The first one carries some vulnerabilities and as we can see in the different repos, it is not soon to be fixed...

* Remove a quirk

Author: GuillaumeAmat

.travis.yml

@@ -3,10 +3,10 @@ language: node_js
 node_js:
 - 8
 before_install:
-- npm install codecov.io coveralls
+- npm install codecov coveralls
 - npm install nwb
 after_success:
-- cat ./coverage/lcov.info | ./node_modules/codecov.io/bin/codecov.io.js
+- cat ./coverage/lcov.info | ./node_modules/.bin/codecov --pipe
 - cat ./coverage/lcov.info | ./node_modules/coveralls/bin/coveralls.js
 branches:
   only: