* vcreate: Add test for `v init`.
* vcreate: Init git properly with no dir arg.
`v init` would fail to create a .gitignore file. When not providing a
dir arg, passing "" to create_git_repo would result in:
```
V panic: failed to create gitignore: failed to open file "/.gitignore"
```
* vcreate: Terminate files with newline.
Fixes#10478.
