UMIP 127 - Add SGDUSD as price identifier

Currently the UMA DVM does not support SGDUSD as price identifier, so we at Jarvis would like this price identifier to be added in order to further expand our Forex tracking synthetic tokens portfolio.

You can view the UMIP here: Create UMIP for SGDUSD to be registered as price identifier by SayWhatDev · Pull Request #398 · UMAprotocol/UMIPs · GitHub

Feel free to ask any questions or raise any concerns in this thread.