Skip clone warming up when a file is missing (#67)

* Skip clone warming up when a file is missing

* Align spacing in help

Add pre-cloning-hook for mirror-prepolulation (#66)

* Add pre-cloning-hook

* Apply suggestions from code review

Styling changes to invoking pre-clone-hook.

* Syntax fix for duplicated unless

* Revert to the check in a separate method due to cyclomatic complexity

Bump to 1.4.5

Merge pull request #63 from square/tsutton/dont-clear-cache-if-auth-e…

…rror

Don't clear cache if an error was authentication-related

Replace all places that can call `Dir.chdir` in thread with passing `…

…chdir` to `Open3.popen2e` (#60)

Add print_git_errors mode (#56)

Add --config

Merge pull request #43 from square/segiddins/retry-and-blow-away-cach…

…e-when-reading-tree-fails

Blow away cache and retry when reading tree fails after clone

Merge pull request #40 from square/jmartin/add-cache-clean-retry-fail…

…ure-mode

Add a new automatic cache clean failure mode 'did not receive expected object'

Version 1.2.3