Move to 2020.4

2020.4 contains a lot of new schemas.
New feature include: new power and thermal schemas, conditions,
and new account types.

For more information, see:
https://www.dmtf.org/sites/default/files/Redfish_Release_2020.4_Overview.pdf



Tested: Validator passes. Able to see new schemas.
Change-Id: I7fb860c84fa4cff80698dcb26a463b155e6faba7
Signed-off-by: Gunnar Mills <gmills@us.ibm.com>