Add support for phar extension

[dpassen]

Needed to install cli tools like phpactor

[autarch]

Hi, thanks for your PR! I'm pretty finicky about my projects (see this blog post for details), so I rarely merge a PR as-is. I can move forward on your PR in one of two ways:

1. I check it out locally, fiddle with it as needed, merge it locally, and simply close this PR. This will preserve at least one commit with your name on it, but the PR will show up as closed in your GitHub stats.
2. If you enable me to push directly to your PR branch (which is the default when you make a PR), I can do my fiddling, then force push to your PR branch and merge the resulting PR. Again, this will preserve at least one commit with your name on it, but you also get credit for the PR merge in your GitHub stats. The only downside is that I will be force pushing directly to your PR branch. Note that this will not work if the PR branch is named master. GitHub doesn't allow me to push to the default branch of your fork.

Please let me know which approach you'd prefer. If I don't hear from you before I get around to working on this PR I'll go with option 1.

Thanks again for your contribution!

[dpassen]

Thanks for the quick response. However this is (hopefully) included, it will make part of my work setup a lot more scriptable and regular.

All things being equal, I’d prefer method 2 but won’t be upset if method 1 is chosen.

Thanks for the clarity and consideration.

[autarch]

Merged, thanks!