backend/atlas: adhere to backend.CLI

backend/atlas/backend_test.go

@@ -8,4 +8,5 @@ import (
 
 func TestImpl(t *testing.T) {
 	var _ backend.Backend = new(Backend)
+	var _ backend.CLI = new(Backend)
 }

backend/atlas/cli.go

@@ -0,0 +1,13 @@
+package atlas
+
+import (
+	"github.com/hashicorp/terraform/backend"
+)
+
+// backend.CLI impl.
+func (b *Backend) CLIInit(opts *backend.CLIOpts) error {
+	b.CLI = opts.CLI
+	b.CLIColor = opts.CLIColor
+	b.ContextOpts = opts.ContextOpts
+	return nil
+}