Updates specs to use new rails5 format.
The old format:
`get :show, { some: params }, { some: headers }`
The new format:
`get :show, params: { some: params }, headers: { some: headers }`
Change "+" icon under "Files" section to have three options:
* Create file
* Upload file
* New directory
Upload file is no longer accessible from the "Create file" page.
Users can now select a target branch in upload file as well.
Closes#2799: Fixes a bug where file modes were overwritten after a commit
Closes https://github.com/gitlabhq/gitlabhq/issues/8253: Existing files
can no longer be overwritten in the "Create file" section.
Closes#2557
