power_stencil fails on a system where git is not installed at all with the following error: ``` /tmp $ power_stencil -V Traceback (most recent call last): 11: from /usr/local/bin/power_stencil:23:in `<main>' 10: from /usr/local/bin/power_stencil:23:in `load' 9: from /var/lib/gems/2.5.0/gems/power_stencil-0.8.3/exe/power_stencil:4:in `<top (required)>' 8: from /usr/lib/ruby/2.5.0/rubygems/core_ext/kernel_require.rb:59:in `require' 7: from /usr/lib/ruby/2.5.0/rubygems/core_ext/kernel_require.rb:59:in `require' 6: from /var/lib/gems/2.5.0/gems/power_stencil-0.8.3/lib/power_stencil.rb:4:in `<top (required)>' 5: from /usr/lib/ruby/2.5.0/rubygems/core_ext/kernel_require.rb:59:in `require' 4: from /usr/lib/ruby/2.5.0/rubygems/core_ext/kernel_require.rb:59:in `require' 3: from /var/lib/gems/2.5.0/gems/git-1.5.0/lib/git.rb:25:in `<top (required)>' 2: from /var/lib/gems/2.5.0/gems/git-1.5.0/lib/git/lib.rb:875:in `meets_required_version?' 1: from /var/lib/gems/2.5.0/gems/git-1.5.0/lib/git/lib.rb:865:in `current_command_version' /var/lib/gems/2.5.0/gems/git-1.5.0/lib/git/lib.rb:967:in `command': git version 2>&1:sh: 1: git: not found (Git::GitExecuteError) ``` Error coming from the `git` gem.