Merge pull request #13 from duckinator/rewrite

Rewrite. (NOTE: Travis build fails; it's fine.)
Bump version to 0.4.0.
Okay, this ACTUALLY fixes the issue with bin/sicuro.
Version bump.
Make bin/sicuro exit with 1 on failure, 0 otherwise.
Bump to 0.5.0 because the API actually changed.
Make it use the CORRECT exit status.
Version bump. Again. I need to find a way to test the executable.
Fix test for syntax error caused by a lone :.
We don't need gist.rb. Gisting isn't Sicuro's job.
Clean up some tests.
Suddenly, I feel incredibly stupid. Closes #9.
Dummy ENV.
Add test to make sure ENV is replaced.
[ci skip] Add build status icon.
ZOMFG CODE STYLE FIXES.
MUSICAL ARRAY FORMATTING. Or something like that.
ZOMFG CODE STYLE FIXES. (Again)
Fixes #15. It wasn't as fundamental as it looked.

Thanks @tsion for finding this.
Update _unsafe_eval() tests.