MaaS provider should expose the bootstrap timeout options.
Update environprovider.go

Updated bootstrap-timeout to 1800 secs by default on MAAS provider.
Update environprovider.go

Just bootstrap-timeout option will be exposed, until this default value is increased
on a per-provider basis.
Merge pull request #18 from niedbalski/bootstrap-boilerplate-timeout

MaaS provider should expose the bootstrap timeout options.

Most of the MAAS deployments takes longer times, in fact a install with d-i typically takes around 20 minutes on a good day.

Would be a good thing to at least have the timeout settings exposed ( commented ) for being
noticed by all users.

Please see reference LP: #1325891