Citylearn challenge 2023 power outage env

[kingsleynweye]

Description

Fixed bug where unserved energy was being calculated even when there was no power outage

Issue

Reverts the change made in #89

Changes

Reverts the change made in #89

Screenshots

NIL

Checklist

• [x] I have tested the changes locally and they work as intended.
• [x] I have updated the documentation, if applicable.
• [x] I have added new tests, if applicable.
• [x] I have added any required dependencies to the requirements.txt file, if applicable.
• [x] I have followed the project's code style and conventions.

Additional notes

NIL