Match the bigtable_instance resource to the API structure, deprecating
the inlined config parameters. This is a complicated deprecation,
because we don't want to ForceNew when updating to use the new
undeprecated fields, but we want to ForceNew if they change.
This is achieved using a CustomizeDiff.
An instance is an abstract container of clusters, it's the cluster that
has the nodes and holds the data, so the number of nodes and location
apply to the cluster.
* govendor fetch cloud.google.com/go/bigtable
* Vendor the rest of the stuff.
* Add support for instance_type to google_bigtable_instance.
* Revendored some packages.
* Removed bad packages from vendor.json
