list *all* invalid options

Before:

```bash

$ ./tcat bob 7 ˚
Invalid option: bob
Options:
  -v, --version print tcat version
  -h, --help    print this help
Help can be found at github.com/marcomorain/tcat
```

After:

```bash

$ ./tcat bob 7 ˚
Invalid option:	bob
Invalid option:	7
Invalid option:	˚

Available Options:
	-v, --version	print tcat version
	-h, --help	print this help

Help can be found at https://github.com/marcomorain/tcat
```