Added 'unknown' to ConferencingProvider#429

samuelpx merged 1 commit intomainnylas/nylas-python:mainfrom

CUST-4563-clone-v-3-python-sdk-conferencing-provider-enum-missing-unknown-value-causes-key-errornylas/nylas-python:CUST-4563-clone-v-3-python-sdk-conferencing-provider-enum-missing-unknown-value-causes-key-errorCopy head branch name to clipboard