Adding validation to branch creation

Author: StanleyGoldman

src/UnityExtension/Assets/Editor/GitHub.Unity/UI/BranchesView.cs

@@ -452,6 +452,8 @@ private void OnCreateGUI()
                     var cannotCreate = selectedNode == null ||
                                        selectedNode.Type == NodeType.Folder ||
                                        newBranchName == null ||
+                                       newBranchName.StartsWith("/") ||
+                                       newBranchName.EndsWith("/") ||
                                        !Utility.BranchNameRegex.IsMatch(newBranchName);
 
                     // Create on return/enter or cancel on escape