The `init` and `copy` commands can now use `--repository-file2` flag and
the `$RESTIC_REPOSITORY_FILE2` environment variable.
This also fixes the conflict with the `--repository-file` and `--repo2`
flag.
Tests are added for the initSecondaryGlobalOpts function.
This adds a NOK function to the test helper functions. This NOK tests if
err is not nil, and otherwise fail the test.
With the NOK function a couple of sad paths are tested in the
initSecondaryGlobalOpts function.
In total the tests checks wether the following are passed correct:
- Password
- PasswordFile
- Repo
- RepositoryFile
The following situation must return an error to pass the test:
- no Repo or RepositoryFile defined
- Repo and RepositoryFile defined both
