Do not create user branch when working with new file

[superdav42]

Follow up for #138

Previous changes did create a user branch if the file requested did not exist in the master branch.

This improved on that so a user branch will NOT be created until the user saves a file.

Turns out it was easy enough to just create a contectObject without fetching it from anywhere. Seems to be working for me but I still don't have access to the usual translator repositories.

Testing instructions in styleguidist:

• Select File Crude -> Create for sidebar or go to http://localhost:6060/#/File%20CRUD?id=section-create
• Login and choose a repository. I testing with superdav42/hbo_obs
• Enter filePath of a file that does NOT exists on master such as newfile.md and something in defaultContent field.
• You should see editor with something in it but no new branch will be created which you can verify at https://bg.door43.org/YOUR_USERNAME/hbo_obs/branches
• Edit content or just click save button.
• New branch will be created at https://bg.door43.org/YOUR_USERNAME/hbo_obs/branches and contain the new content in newfile.md

[jincypjose]

look's good to me