command/e2etest: Temporarily disable tests that access network

Several of these tests rely on external services (e.g. Terraform Registry)
that have not yet been updated to support the needs of Terraform v0.12.0,
so for now we'll skip all of these tests and wait until those systems have
been updated.

This should be removed before Terraform v0.12.0 final to enable these
tests to be used as part of pre-release smoke testing.

command/e2etest/main_test.go

@@ -56,4 +56,10 @@ func skipIfCannotAccessNetwork(t *testing.T) {
 	if !canAccessNetwork() {
 		t.Skip("network access not allowed; use TF_ACC=1 to enable")
 	}
+
+	// During the early part of the Terraform v0.12 release process, certain
+	// upstream resources are not yet ready to support it and so these
+	// tests cannot be run. These will be re-enabled prior to Terraform v0.12.0
+	// final.
+	t.Skip("all tests with external network access are temporarily disabled until upstream services are updated")
 }