Record Twitter Handles

[RogerTangos]

AS A Social Media Manager
I WANT brands to have twitter handles listed
SO THAT I can know how to reach out to them, and possibly automate this process in the future

Dev Details:

• Wikidata, b-impact, and possigly GABV has twitter handle information for various banks.
• The results of this may be used to contact banks and shame them into filling out HR questionnaires

Acceptance criteria:

• Add a twitter field to the wikidata, bimpact, and possibly gabv datasource implementations
• Harvest twitter data from the above data sources, modifying their ingest functions
• Add a twitter handle field to each brand
• Create a merge strategy for twitter fields.