Added persistent history file to main.py

Author: kmvanbrunt

.gitignore

@@ -25,3 +25,6 @@ htmlcov
 # mypy plugin for PyCharm
 dmypy.json
 dmypy.sock
+
+# cmd2 history file used in main.py
+cmd2_history.txt

main.py

@@ -7,6 +7,6 @@
 
     # Set "use_ipython" to True to include the ipy command if IPython is installed, which supports advanced interactive
     # debugging of your application via introspection on self.
-    app = cmd2.Cmd(use_ipython=True)
+    app = cmd2.Cmd(use_ipython=True, persistent_history_file='cmd2_history.txt')
     app.locals_in_py = True
     app.cmdloop()