Accommodating Schema Version 0.9.1 for classifier module

[hernandezc1]

ELAsTiCC has updated their alert & broker classification schema to version 0.9.1 This PR serves to update:

• [x] the elasticc.[schema version].brokerClassfication.avsc file to version 0.9.1
• [x] the elasticc-schema-map.yml file
• [x] main.py for the classifier module to accommodate schema version 0.9.1
• [x] the requirements.txt file for the classifier module to accommodate v0.2.47 of broker_utils

An instance of the classifier module (with these updates included) has been deployed and tested. Testing was successful, and the classification results written to BigQuery can be accessed here (testid = elasticc2test)

[hernandezc1]

I'm having some issues loading an alert (and hope to talk more about that in our next meeting). I believe I remember Rob saying that the alert schemas should be identical to version 0.9, but I will double check this is correct

[hernandezc1]

@troyraen looks like there was an argument that I had forgotten to remove during our review last meeting (it was --max-delivery-attempts). This was causing setup.sh to crash when trying to create the trigger subscription for the Cloud Run module. I've removed the argument and tested the script again. Everything worked on my end, let me know if anything else comes up