* Add function to update minimum gas price
* Update TestMinerService to handle min_gas_price changes
* Place minimum gas price test behind feature flag
* Update check for fixed gas pricer to be more explicit
* Use errors::unsupported instead of errors::request_rejected
* Add test that fails to set minimum gas price
* Fix test that should fail when setting new gas price
* Put dev dependencies behind feature flag
* Fix deadlock in set_minimal_gas_price()
* Update RPC tests with mocked error response
* Remove unnecessary cfg flag
* Remove duplicate crate imports