Latest distribution tarball

add shell.nix (#175)

Tests had to be lightly changed to support installation under Nix.

Added a Nix testing target to run all tests under Nix.

v0.2.0

• Refactor tests.
• Improved linting.
• Hide try-internal variables from scripts.
• Style guide.
• Testing in Vagrant.
• Support nested mounts.
• Resolve issues with userxattr.
• Better support for unionfs.
• Use /bin/sh, not /bin/bash.
• -i flag to ignore paths.
• Interactive improvements.

v0.1.0

Initial release.