Fixed minor bug in CPAN::Mini::Inject::inject() if verbose.

[WolfgangPecho]

CPAN::Mini::Inject::inject() reports only the first module of a dist file if verbose is on. It should report each injected Module for each dist file.

The line

 next if $already_injected{$file}++; 

prevented printing of other modules.

[simbabque]

@wchristian I've reviewed this PR as part of my Pull Request Challenge entry for September 2017 and think it can be merged without problems. There's the one thing I think could be a bit more convenient, but that's trivial to add.

Updating the documentation might make sense too.

Passing a value to "inject" enables verbose mode, which lists each module as it's injected.

could become something like

Passing a value to "inject" enables verbose mode, which produces a report of all injected modules.

[briandfoy]

I've cherry-picked this into briandfoy/cpan-mini-inject@93b4e0d1fd5d3c85ca2c2bdb00dcd570c7a42e73

[briandfoy]

This is part of 1.002. I can't close this issue though. Thanks,