multiple pairs

[dcposch]

for the proof of concept, we have just one pair: ropsten ETH / testnet BTC.

for production, we can have ETH / BTC, but also others:

• WBTC / BTC . decentralized, without Wrapped's onerous onboarding process. the spreads here should be much tighter than what's possible on ETH/BTC.
• ETH / ZEC
• WZEC / ZEC

[0xClandestine]

I would suggest modifying the portal so that it allows any ERC20 to be used not just what's defined in the constructor, so that by default you could offer pairs for any BTC/ERC20 pair. This would also prevent the need for a "portal router" down the road.