Add Python 3.10 support

[dbfreem]

The current version on web3.py that is being upgraded to in #339 supports python 3.7.2 through python 3.9. Once web3.py releases their v6 release then web3.py will support python 3.10

Items needed to support 3.10

• web3.py v6
• CI in ethereum-etl would need to be added for 3.10

Does anyone else know of any other changes that may be needed to move ethereum-etl to python 3.10 support.

[goshasty]

Hello!
It seems that web3 released v6 version
Could ethereum-etl be upgraded?