Review and add additional tests for Cisco and Arista sensitive lines

[sfraint]

Some password regexes for Cisco-like configs in sensitive_item_removal.py are unverified and untested.

They need to be tested against a variety of config lines generated on a router (to make sure the regex handles different syntaxes allowed in the line) and these config lines should be added to the existing list of test lines in test_sensitive_item_removal.py.