v2.3.1

• Remove dependency on moment.js with formatDate function (Thanks to https://github.com/AndreasGassmann)
• Move TypeScript @types/* to dev deps (Thanks to https://github.com/AndreasGassmann)
• Update to @polkadot/wasm-crypto 1.0
• Cleanup dependencies to pave the way for using yarnpkg 2 (Explicit instead of implicit)