122.cli.separate

[cwhitlock-NOAA]

Describe your changes

Adding pytest command-line tests for the fre $TOOL utilities and fre pp $TOOL utilities

Issue ticket number and link (if applicable)

Issue #122

Checklist before requesting a review

• [ x] I ran my code
• [ x] I tried to make my code readable
• I tried to comment my code
• [ x] I wrote a new test, if applicable
• [ x] I wrote new instructions/documentation, if applicable
• [ x] I ran pytest and inspected it's output
• I ran pylint and attempted to implement some of it's feedback

[ilaflott]

Looks great to me! all tests pass too