Ensure that we cannot proceed if outpath is '.' (cwd/root); bump version

Per https://github.com/docpad/docpad-plugin-ghpages/issues/6 deploy-ghpages fails if outPath is set to '.', because it removes .git, etc. The right way to do it is to output to ./out, push that to ghpages, then clean it up, which is how it does it.

Net: this is just a safety check. If not, it might fail *and* wipe out a user's .git directory.