Aion Pool3 0.1.2 release

1. Modified the block rewards calculator for the Aion kernel SignatureSchemeSwap protocol upgrade.

Migration guide from version 0.1.1:

To support the Aion kernel SignatureSchemeSwap protocol, the pool operator need to modify the current pool config file (i.e. aion_pool.json). Add

"signatureSwapProtocolUpgradeBlock": [protocol upgrade block number],

under the "pools" object array.
https://github.com/aionnetwork/aion_pool3/blob/b06e3bfa699c5a156acc43d46bc28653aeab591e/aion_pool/examples/aion_pool.json#L64

Aion Pool3 - 0.1.1

1. Fix Relay message issue
2. Fix segment fault error

Aion Pool3 - 0.1.0

1. Support minimum payment for miners
2. Rust Kernel compatibility
3. Deprecate BlockRefreshInterval configuration.
4. Bug Fixes