fix project creation issues

[xmo-odoo]

Been creating a few more projects recently so people get the forwardbot, and there are a few issues with project creation:

• since the bots are generally identical, being able to [duplicate] a project and get the basic bot configuration would be nice (probably not the repos and branches)
• there's a weird error when setting a mergebot token as it tries to retrieve the identification and complains
• trying to save with a valid token fails entirely, but it's possible to save with an invalid token, then change the token to the valid one, which makes no fucking sense
• when creating multiple branches at the same time, their order is completely out of whack and the project ends up shitting the bed, assuming the branches are sent in the correct order to create we should simply set their sequence during the Project.create.