Mainnet Release v0.5.1

What's Changed

• [Maintenance] Fix assertion of maintenance elapsed by @nxqbao in #217
• [Staking] Remove cooldown when undelegate for renouncing candidate by @nxqbao in #216
• [Deploy] Add deployment artifacts for testnet by @minh-bq in #219
• Remove @axie package by @nxqbao in #220
• [test] Fix assertion on arrays of BigNumbers by @nxqbao in #222
• [upgrade] Script for set min commission rate by @nxqbao in #221
• [Upgrade] Fix set commission rate script by @nxqbao in #225
• v0.5.1 by @nxqbao in #223

Full Changelog: v0.5.0...v0.5.1