update libsodium-wrappers-sumo dependency to 0.8.x

[cthayer]

The current versioning of the libsodium-wrappers-sumu dependency is ^0.7.11 which resolves to version 0.7.16.

Version 0.7.16 of libsodium-wrappers* has a known error that breaks functionality for new npm installs that use interchainjs:

Module not found: Can't resolve './libsodium-sumo.mjs'

This is fixed by upgrading to 0.8.x or downgrading to 0.7.15. I think upgrading the dependency versioning to ^0.8.2 is the best approach.

Reference: jedisct1/libsodium.js#360