* fix: relax trait bounds on JsonRpcClient
* refactor(provider): move http client to separate dir
* feat(provider): add initial Websocket support over Stream/Sink + Tungstenite
* test(provider): add websocket test
* feat(provider): add convenience method using tokio/async-std behind a feature flag
* test(provider): add websocket ssl test
* feat(provider): add TLS websockets for tokio/async-std
* docs(provider): add websocket docs / examples
* fix(provider): make tokio an optional dep
* fix(provider): do not pass a param to estimate_gas
* fix(provider): pass correct number of args to new_filter
* test(signer): add test to ensure that the Pending block number works
* docs: fix links
* feat(types): add optional Celo support
* feat: add Celo feature flags to all crates
* test(provider): add get_transaction celo test
* test(signer): add send_transaction celo test
* test(contract): add deploy and call contract function celo test
* fix(provider): ensure the Pending transaction calls the waker to get polled again
* feat(core): allow setting the blocktime in ganache
* test(provider): move pending txs test to integration tests + use block time
* fix(signers): make EIP-155 optional and fix sighash generation bug
Georgios Konstantopoulos