avoid use magic number to alloc toolbar

Classes/Editing/Argument Input Views/FLEXArgumentInputTextView.m

@@ -40,7 +40,8 @@
 
 - (UIToolbar*)createToolBar
 {
-    UIToolbar *toolBar = [[UIToolbar alloc] initWithFrame:CGRectMake(0, 0, [UIScreen mainScreen].bounds.size.width, 50)];
+    UIToolbar *toolBar = [UIToolbar new];
+    [toolBar sizeToFit];
     UIBarButtonItem *spaceItem = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemFlexibleSpace target:nil action:nil];
     UIBarButtonItem *doneItem = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemDone target:self action:@selector(textViewDone)];
     toolBar.items = @[spaceItem, doneItem];