Added StandardError to list of highlighted exceptions

dotfiles/vim/syntax/python.vim

@@ -422,6 +422,7 @@ if s:Enabled("g:python_highlight_exceptions")
 
     syn keyword pythonExClass	ResourceWarning
   endif
+  syn keyword pythonExClass	StandardError
   syn keyword pythonExClass	BaseException
   syn keyword pythonExClass	Exception ArithmeticError
   syn keyword pythonExClass	LookupError EnvironmentError