Add support for tgz (tar+gzip) output
Don't include target/ directory element on output tar
New :output-dir option. Defaults to project's `target` dir.

Note: this is a breaking change, since the old default was the project's root dir.
Generating the archive under `target` directory makes more sense and plays nicer with
others like `lein clean` and `lein-package`
Release 3.0.0.
+ Possibility to specify :tar-gz for getting a .tar.gz suffix (non-breaking change)
+Add small hint to README.md, that :tar-gz is possible
Add --name option to allow custom name/dir

Changing the filename after-the-fact is simple but that still leaves the
problem of the directory inside the tar.  --name (or -n) will alter both
the name of the resulting file as well as the directory inside the tar.
Merge pull request #13 from leathekd/custom-tar-name

Add --name option to allow custom name/dir
Release 3.2.0
Update README installation section with latest released version.
Merge pull request #14 from dacamo76/update-version-in-readme

Update README installation section with latest released version.