Most of the state package has been deprecated by the states package.
This PR replaces all the references to the old state package that
can be done simply - the low-hanging fruit.
* states: move state.Locker to statemgr
The state.Locker interface was a wrapper around a statemgr.Full, so
moving this was relatively straightforward.
* command: remove unnecessary use of state package for writing local terraform state files
* move state.LocalState into terraform package
state.LocalState is responsible for managing terraform.States, so it
made sense (to me) to move it into the terraform package.
* slight change of heart: move state.LocalState into clistate instead of
terraform
To allow using the same Tablestore table with multiple OSS buckets.
e.g. instead of env:/some/path/terraform.tfstate
the LockID now becomes some-bucket/env:/some/path/terraform.tfstate
faster
The acceptance tests for etcdv3, oss and manta were not validating
required env variablea, chosing to assume that if one was running
acceptance tests they had already configured the credentials.
It was not always clear if this was a bug in the tests or the provider,
so I opted to make the tests fail faster when required attributes were
unset (or "").