re-enable and fix module variable tests
re-enable and fix module variable tests

A few tests were inadvertently renamed, causing them to be be skipped.
For some reason this is not caught by the `vet` pass that happens during
normal testing.

hashicorp/terraform,hashicorp/terraform,pdecat/terraform,apparentlymart/terraform,ewbankkit/terraform,apparentlymart/terraform,ewbankkit/terraform,pdecat/terraform,apparentlymart/terraform,hashicorp/terraform,rnaveiras/terraform,pdecat/terraform,rnaveiras/terraform,ewbankkit/terraform,apparentlymart/terraform,tommynsong/terraform,pdecat/terraform,apparentlymart/terraform,ewbankkit/terraform,tommynsong/terraform,tommynsong/terraform,rnaveiras/terraform