New project creation should be in a transaction - so that users are not left to "clean up" after a failure

[joshuawilson]

From @ldimaggi on June 12, 2017 18:33

If user attempts to add a new project to a space, and project creation fails, the user can be left with unwanted assets (github repo, pipeline, etc.)

See: fabric8-ui/fabric8-ui#1498

It would be much better for the user if the project creation were enclosed in a transaction, and if the user were given the option of cleaning up in the event of a failure.

Copied from original issue: fabric8-ui/fabric8-ui#1499