move node_js version to nvmrc

[stephengroat]

removes node js travis dependency
improves compatability with node version managers

[lauthieb]

Thanks @stephengroat for this. We are investigating this bug #110 so nothing can be merged before its correction but after I will merge your proposition ;)

[lauthieb]

@stephengroat Can you please fix conflicts and update your branch with just your modifications?
Sorry for the inconvenience it was mandatory to force push master after several tries to fix this important bug #110

Here you can download the new version 1.2.3 : https://github.com/lauthieb/code-notes/releases/tag/1.2.3

Thanks a lot in advance for this.

[stephengroat]

@lauthieb fixed

[lauthieb]

Thanks @stephengroat

[lauthieb]

@stephengroat sorry but the CI is broken with your suggestion.

[stephengroat]

@lauthieb could you try a rerun on travis?

all this PR does is move the nvm install step from a hard-coded value to a value pulled from the .nvmrc file (compare failure here https://travis-ci.org/lauthieb/code-notes/jobs/622698139#L87 and success on master https://travis-ci.org/lauthieb/code-notes/jobs/622661291#L73)

since that's the only difference, i don't think this should have any effect

[lauthieb]

Okay for me & Travis CI!
Thanks @stephengroat :)