Partial fix for finding hook executables
Partial fix for finding hook executables

This allows, at least, more executables to be picked up.

It doesn't pick up group-executable scripts and ignore xattr files but
it should be better than what was there before.

Closes #80

fgandellini/rcm,fgandellini/rcm,zachlatta/rcm,thoughtbot/rcm,zachlatta/rcm,thoughtbot/rcm,devm33/rcm,TheLinuxKitten/rcm,zachlatta/rcm,TheLinuxKitten/rcm,ali/rcm,ali/rcm,tejasmanohar/rcm,TheLinuxKitten/rcm,thoughtbot/rcm,Frost/rcm,devm33/rcm,ali/rcm,ali/rcm,fgandellini/rcm,tejasmanohar/rcm,tejasmanohar/rcm,devm33/rcm,TheLinuxKitten/rcm,Frost/rcm,Frost/rcm,zachlatta/rcm,tejasmanohar/rcm,devm33/rcm,fgandellini/rcm,Frost/rcm