Fix straprc for 2 edge cases

[charliegetzen-okta]

Edge case 1 - using an ls alternative

See #7
This is remediated by surfacing errors so folks can see what is going on.

Edge case 2 - using dot files

If you were to put a .test.sh file in straprc.d, it would be picked up by ls -A, however, it would NOT be picked up by for file in "${HOME}"/.strap/etc/straprc.d/*.sh; do
In this scenario, one of two things could happen:

1. There are only dot-files in straprc.d - this will cause errors because the for-loop globbing will fail
2. There are regular files and dot-files - The dot files will be ignored