Update README to reflect new download location

[jboning]

Github seems to have moved to hosting files at githubusercontent.com.

[fgb]

#12 is a duplicate pull request that also replaces wget with curl.

[fingolfin]

For the record, I merged a variant of pr #12 into my git-remote-hg fork at https://github.com/fingolfin/git-remote-hg.

[felipec]

Is this really needed? Both locations seem to work, and the main location seems to be:

https://github.com/felipec/git-remote-hg/raw/master/git-remote-hg

[fgb]

Notice that the link you provided redirects to https://raw.githubusercontent.com/felipec/git-remote-hg/master/git-remote-hg, which should probably be considered the main location. The githubusercontent domain was introduced back in April 2014 to prevent some cross-domain vulnerabilities: https://developer.github.com/changes/2014-04-25-user-content-security/.