fix: TFE remote ops detection for >= tf 1.0.0 (#1687)

Author: taavitani

server/core/runtime/plan_step_runner.go

@@ -63,7 +63,7 @@ func (p *PlanStepRunner) isRemoteOpsErr(output string, err error) bool {
 	if err == nil {
 		return false
 	}
-	return strings.Contains(output, remoteOpsErr01114) || strings.Contains(output, remoteOpsErr012)
+	return strings.Contains(output, remoteOpsErr01114) || strings.Contains(output, remoteOpsErr012) || strings.Contains(output, remoteOpsErr100)
 }
 
 // remotePlan runs a terraform plan command compatible with TFE remote
@@ -332,6 +332,14 @@ locally at this time.
 
 `
 
+// remoteOpsErr100 is the error terraform plan will retrun if this project is
+// using TFE remote operations in TF 1.0.{0,1}.
+var remoteOpsErr100 = `Error: Saving a generated plan is currently not supported
+
+The "remote" backend does not support saving the generated execution plan
+locally at this time.
+`
+
 // remoteOpsHeader is the header we add to the planfile if this plan was
 // generated using TFE remote operations.
 var remoteOpsHeader = "Atlantis: this plan was created by remote ops\n"