This also includes two derived options `--from-insecure-no-password`
used for commands that require specifying a source repository. And
`--new-insecure-no-password` for the `key add` and `key passwd`
commands.
Specifying `--insecure-no-password` disabled the password prompt and
immediately uses an empty password. Passing a password via CLI option or
environment variable at the same time is an error.
The behavior of the new option should reflect the behavior of normal backups: when the command exit code is zero and there is no output in the stdout, emit a warning but create the snapshot. This commit fixes the integration tests and the ReadCloserCommand struct.
The tests are now split into individual files for each command. The
separation isn't perfect as many tests make use of multiple commands. In
particular `init`, `backup`, `check` and `list` are used by a larger
number of test cases.
Most tests now reside in files name cmd_<name>_integration_test.go. This
provides a certain indication which commands have significant test
coverage.
