Install exact version is not possible

[attenzione]

Can't install the exact version, however it's mentioned in README.

[tersmitten]

Apparently that was added in https://github.com/Oefenweb/ansible-nodejs/commit/97d46020224617b7b6fe31fbf77ad020b090255f#diff-b335630551682c19a781afebcf4d07bf978fb1f8ac04c6bf87428ed5106870f5, but it's not true.

[attenzione]

Yes, I saw this commit. But then nodejs_version_map isn't working. I advise removing this in README unless someone wants to fix it :)

[tersmitten]

Yes, so the comment should be removed

[tersmitten]

See #19