CLI - Support Underscored Routes

[pfeytser]

No description provided.

[nelsonpecora]

The fix for this is:

• use underscored routes by default
• add a --amphora-version <integer> flag
• if the amphora version is set to 4 (or lower), use non-underscored routes

(note: we're doing this, rather than a binary --no-underscored-routes flag, because the amphora api might change in future versions. this way, we'll be able to use claycli with multiple amphora versions without having to checkout different claycli versions, which is a hassle)

[nelsonpecora]

Actually, we'd need to split it into two flags anyway (it's possible to import from an old version of amphora to a new version), and this is a common enough use case that it should be fast to write. Thus, we should do:

• --amphora-legacy, -a use non-underscored api routes (applies like --key)
• --source-amphora-legacy, -A use non-underscored api routes (applies like --source-key)

[nelsonpecora]

We're actually going to handle this dynamically, but for now I've made a major version of claycli with hardcoded underscore support.