Review test cases for BLS firewall impacts

[schmidtDETR]

Two items to review for the testing suite:

1. Many tests point to the BLS ce database, which is relatively large (the ce.series file is nearly 4MB). Would optimize results to point to a smaller file like JOLTS (jt.series is 158KB).
2. Test cases are now routinely throwing a 403 error during testing runs, possibly because Github R CMD Check is running multiple environments running the same tests and hitting the same BLS files in rapid succession. May need to incorporate calls to set the environment variable BLS_USER_AGENT during tests, possibly in a way that makes these tests distinct from individual users to avoid operational impacts?