Add agency_email attribute to hibernate configurations

[RanAbram]

Summary:

The agency_email attribute already introduced for the agency entity in the past, but it seems that this field not being parsed as part of the hibernate import. The field is part of the GTFS spec and can be found here. This PR should fix that.

Expected behavior:

When using the hibernate GtfsDatabaseLoaderMain we are expecting to get the agency_email field to the gtfs_agencies table.

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• [ ] Run the unit tests with mvn test to make sure you didn't break anything
• [ ] Format the title like "Fix # - short description of fix and changes"
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[RanAbram]

Hi @jeffmaki @sheldonabrown , How are you doing?

I could see that lately you merged couple of new PRs into master. For that reason, I was wondering if there's any chance that you could please review my PR as well?

Thanks!