Allow updating cache without apikey

[nhaydel]

This PR is apart of the membership levers project.

We want to allow users who don't know their api key or don't have a valid api key to still pull rules from the library and update the cache. This PR just updates the cache populator to allow fetching rules only as well as handle any failed requests to the cdisc library api.

The expected outcomes are:

• Running the update_cache function without an api key should result in a log message saying only the rules will be updated. Only the save_rules_locally function should be run.

Note

Since the ability to request rules from the production library api without an api key has not been released you will see 401 responses from the rules endpoint as well. This should be resolved once that functionality is released. If you want to ensure the rules are updated, you can use the dev environment.

• Running the update_cache function with an invalid api key should result in all failed requests being logged and the cache should not get updated.

[gerrycampion]

i think you should add documentation describing the new behavior in this section: https://github.com/cdisc-org/cdisc-rules-engine/blob/allow-update-cache-without-apikey/README.md#updating-the-cache-update-cache