Add REMOVING router status and update transitions

src/main/java/com/litoralregas/openvpn/router/RouterController.java

@@ -74,7 +74,7 @@ public class RouterController {
                     result.stdout()
             );
 
-            service.forceStatus(id, RouterStatus.PROVISIONED);
+            service.forceStatus(id, RouterStatus.REMOVING);
 
             return DeploymentResponse.from(finishedDeployment);
         } catch (Exception exception) {

src/main/java/com/litoralregas/openvpn/router/RouterService.java

@@ -69,9 +69,18 @@ public class RouterService {
 
     private boolean isValidTransition(RouterStatus current, RouterStatus next) {
         return switch (current) {
-            case PENDING, FAILED -> next == RouterStatus.PROVISIONING || next == RouterStatus.REMOVED;
-            case PROVISIONING -> next == RouterStatus.PROVISIONED || next == RouterStatus.FAILED;
-            case PROVISIONED -> next == RouterStatus.REMOVED;
+            case PENDING, FAILED ->
+                    next == RouterStatus.PROVISIONING || next == RouterStatus.REMOVING;
+
+            case PROVISIONING ->
+                    next == RouterStatus.PROVISIONED || next == RouterStatus.FAILED;
+
+            case PROVISIONED ->
+                    next == RouterStatus.REMOVING;
+
+            case REMOVING ->
+                    next == RouterStatus.REMOVED || next == RouterStatus.FAILED;
+
             case REMOVED -> false;
         };
     }

src/main/java/com/litoralregas/openvpn/router/RouterStatus.java

@@ -5,5 +5,6 @@ public enum RouterStatus {
     PROVISIONING,
     PROVISIONED,
     FAILED,
+    REMOVING,
     REMOVED
 }