Handle unset git information
Handle unset git information

In CI or in a new user's case they may not have properly configured
their git information prior to running the bootstrap command. This
change temporarily adds a name and email for the initial bootstrap
commit if the global information is not set. Instructions on how to
configure this are also provided when this case occurs.

Change-Id: Ib1916b11ec4cb544079075c7602081a147925067

openstack/puppet-openstack-cookiecutter,openstack/puppet-openstack-cookiecutter,openstack/puppet-openstack-cookiecutter