add support for contentful-cli

[cmugla]

some of the issues we've found so far with ctf-migrate that have been pretty annoying:

• no "real" down migrations. all entries need to be deleted before content-type can be deleted. (this doesn't matter if you're only doing "forward only migrations" i guess!)
• no rate limiter for api requests. so if you run a large amount of migrations it chokes
  and most recently (we wrote script to deal with these things)
• migrations just flat out stopped working a couple weeks ago possibly related to this issue: Support newer version of contentful-migration  deluan/contentful-migrate#28, deluan has been slow to get pr for the fix merged.

from @sssyed 🙏

Adding support for contentful-cli (and/or deprecating support for ctf-migrate) may be needed - please look into this