[#61159076] change api_key to the default (in CRM)
[#61159076] Typo (there's a method named merge)
[#61159076] if state is pending merge controller must return 202
[#61159076] Check if the Merge already exists
[#61159076] Stub activity stream merge

Now that we give a 202 response when merge is pending we need to really
merge the contacts
[#61159076] Add uniqueness validation