Generate a lock file with the same name of the original Berksfile

[gionn]

Hi,

berks command has a nice -b parameter so it's possibile to use an alternate configuration file name instead of the default Berksfile (this is good to have multiple Berksfile pointing to different cookbooks in the same directory).

Unfortunately when doing berks install, both them overwrite the same Berksfile.lock in the current directory, impacting notably on the usefulness of the -b switch.

The Berksfile.lock should be created using the same pattern name of the original Berksfile used with -b switch, so it will be possible to use and commit multiple Berksfile in the same directory.

[sethvargo]

Hi @gionn thank you for the bug report. Would you like to take a stab at fixing it?