Allow POAP verification via xDai

[gdixon]

User Story

As a user, I would like to verify my POAP tokens without moving them to mainnet.

Why Is this Needed

Summary:
The majority of POAP tokens are currently being issued on xDai - users would need to move them to mainnet if they wanted to verify their personhood - given the current gas prices, this is a limiting factor for many of our users.

Description

Type:
Feature

Current Behavior

Currently we only check mainnet for POAP tokens that were issued > 15 days ago

Expected Behavior

I would expect to be able to verify my POAP tokens without moving them to mainnet

Definition of Done

When users are able to verify POAP tokens on xDai

Data Requirements

By the number of users who verify their POAP tokens on xDai

Additional Information

POAP uses the same contract address on xDai and registered their contract in block 12188423