Add provisioning of build machine to instructions for staging machines
Add provisioning of build machine to instructions for staging machines

Since the provisioning of the staging VMs will error out with an error
message if the build machines are not provisioned, we should include
this step in the instructions in the documentation.

micahflee/securedrop,heartsucker/securedrop,micahflee/securedrop,micahflee/securedrop,conorsch/securedrop,garrettr/securedrop,heartsucker/securedrop,garrettr/securedrop,ehartsuyker/securedrop,garrettr/securedrop,ehartsuyker/securedrop,ageis/securedrop,ageis/securedrop,ehartsuyker/securedrop,conorsch/securedrop,conorsch/securedrop,conorsch/securedrop,ehartsuyker/securedrop,ageis/securedrop,garrettr/securedrop,heartsucker/securedrop,ageis/securedrop,heartsucker/securedrop,ehartsuyker/securedrop,conorsch/securedrop,ehartsuyker/securedrop,heartsucker/securedrop,micahflee/securedrop