v0.7.2 - Snarling Chub

Features:

• Version command to print-out the project's version, see #147

Fixes:

• Don't consider a Git refs to be a version number, see #169
• Use installed spec for executing scripts, see #143
• Don't expect shard.lock when shard.yml has no dependencies, see #145
• Compatibility with Crystal 0.24.0 (unreleased)
• Harmonize error messages
• Correct shard.yml parse error line:column reporting