Change "main" script in package.json

[toptalo]

change "main" script in package.json for correct requre() in node

[stubbornella]

This seems to only change the path from src to dist, is that intentional?

[toptalo]

For now csslint uses src version of parser-lib and dist version is redundant
I think it wrong

Also it will be better to exclude src dir from package for size decrease

[toptalo]

Hmm.
Its looks like this change will broke CI tests. Because new tests will run on old builded lib