Don't give up after a failed send.

If for some reason the send action fails (unstable connection for
example), cpanm-reporter would die and the user would need to
restart from begin and this is bad because it will keep dying
everytime and it's almost impossible to send a big list of reports.

Now, cpanm-reporter warns the user that it failed for that one
(so the user may try to run cpanm-reporter again after) but continues
to the next report.

This should be enough to close #5.