bump some of our core dependencies (#7563)

* updated ethereum-types and tiny-keccak

* Updated several deps

* Updated several more dependencies

* Modify dummy file to trigger ci

* fixed update of memmap to 0.6 in ethash crate

* Fixed fetch after update to latest reqwest

* Updated jsonrpc-core with fixes for serde

* add expects in util/version/build.rs

ethcore/native_contracts/generator/Cargo.toml

@@ -6,4 +6,4 @@ authors = ["Parity Technologies <admin@parity.io>"]
 
 [dependencies]
 ethabi = "4.0"
-heck = "0.2"
+heck = "0.3"