Update hBTC to hemiBTC in testnet

[gndelia]

The current address for hemi bitcoin in testnet is 0x36Ab5Dba83d5d470F670BC4c06d7Da685d9afAe7. However, this address has the old symbol name (hBTC instead of hemiBTC).

Leaving this issue once the contract is re-deployed on testnet (Address is still TBD)

[gabmontes]

@max-sanchez is this token contract going to be replaced?