Updated do_install_this() to unlink the .version file if it exists.  This allows installed_perls() to recognize that do_install_this() changed the version.
Updated do_install_this() to unlink the .version file if it exists.  This
allows installed_perls() to recognize that do_install_this() changed the
version.

ref: https://github.com/gugod/App-perlbrew/issues/410

ptolemarch/App-perlbrew,josl/App-perlbrew,rafl/App-perlbrew,ptolemarch/App-perlbrew,josl/App-perlbrew,Asuza/App-perlbrew,Asuza/App-perlbrew,Asuza/App-perlbrew,ptolemarch/App-perlbrew,calid/App-perlbrew,calid/App-perlbrew,josl/App-perlbrew,rafl/App-perlbrew,rafl/App-perlbrew