Allow bootstrap to continue if monit isn't found

The MONIT assignment returns a non-zero status if monit is not found.
Exiting the script immediately at this point is probably not the
desired behavior.
Remove redundant check for monit during upgrade
Upgrade only if certs directory is present
Allow error messages to be printed during build
Merge pull request #1588 from cdonati/bootstrap-monit-check

Allow bootstrap to continue if monit isn't found. Thanks Chris.