Clear password after authentication and add username / pass prompt

[nbr23]

Allow no username nor password to be passed to constructor. In this case, user will be prompted for it on login() call.

Checklist

• [ ] Added tests for changed code.
• [ ] Updated documentation for changed code.
• [x] I've added a news fragment of my changes with the name, "{ISSUE_NUM}.{feature|bugfix|doc|removal|misc}""

Description

• Clear "password" property from SessionManager after login is successful. This prevents us from saving the password on disk in cleartext, and keeping the password in memory after we have successfully performed the oauth authentication does not appear to be needed.
• Allow Robinhood() call without username and password, prompt user for both fields when login() is called if not previously set.

[stale[bot]]

This pull request has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[xConde]

This would be pretty useful.

[stale[bot]]

This pull request has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[stale[bot]]

Closing this pull request automatically because it has not had any activity since it has been marked as stale. If you think it is still relevant and should be addressed, feel free to open a new one.