Fix the service name in the email that tells about new members
Hotfix: Fix typo
Merge pull request #674 from sharetribe/member-joined-mail-fix

Fix the service name in the email that tells about new members
New translations [skip ci]
Create transactions_api.md
Update transactions_api.md
Update transactions_api.md
Merge pull request #676 from sharetribe/transaction_api_spec

Create transactions_api.md
Add billing agreement created spec
Make receipt id optional
Add paypal refunds
Paypal refunding service and ipn handling