Merge pull request #3 from nlnwa/fix/nil-pointer-exception

Fix nil pointer exception

Merge pull request #1 from nlnwa/feat/md5sum-formatted-checksum-file

Use "md5sum -b" style separator in generated checksum files

fix: only use basename of filepath in generated checksum file

fix: use temp dir as specified by flag

This commit fixes the temp dir path to be exactly as specified
by the provided flag. By appending a suffix path the validation
will fail spuriously because the temp dir cannot be accessed if it
does not exist.

Initial commit