Alternating config for Aura consensus mechanism (#21)

* go modules added; preparing to write aura consensus

* adding goerli flag

* goerli flag added

* adding configs

* core/vm: Hide read only flag from Interpreter interface (ethereum#17461) (#6)

Makes Interface interface a bit more stateless and abstract.

Obviously this change is dictated by EVMC design. The EVMC tries to keep the responsibility for EVM features totally inside the VMs, if feasible. This makes VM "stateless" because VM does not need to pass any information between executions, all information is included in parameters of the execute function.

* configuring genesis

* removing duplicate imports

* adding configs for aura api

* configuring goerli cli flag

* flag function fix

* modifying configs

params/config.go

@@ -116,7 +116,7 @@ var (
 	// adding flags to the config to also have to set these fields.
 	AllCliqueProtocolChanges = &ChainConfig{big.NewInt(1337), big.NewInt(0), nil, false, big.NewInt(0), common.Hash{}, big.NewInt(0), big.NewInt(0), big.NewInt(0), nil, nil, &CliqueConfig{Period: 0, Epoch: 30000}, nil}
 
-	AuraProtocolChanges = &ChainConfig{big.NewInt(5), big.NewInt(2), nil, false, big.NewInt(2), common.Hash{}, big.NewInt(3), big.NewInt(3), big.NewInt(1035301), nil, nil, nil, &AuraConfig{Period: 15, Epoch: 30000, Authorities: []string{"0x540a9fe3d2381016dec8ffba7235c6fb00b0f942"}, Difficulty: big.NewInt(131072)}}
+	AuraProtocolChanges = &ChainConfig{big.NewInt(5), big.NewInt(2), nil, false, big.NewInt(2), common.Hash{}, big.NewInt(0), big.NewInt(0), big.NewInt(0), nil, nil, nil, &AuraConfig{Period: 15, Epoch: 30000, Authorities: []string{"0x540a9fe3d2381016dec8ffba7235c6fb00b0f942"}, Difficulty: big.NewInt(131072)}}
 
 	TestChainConfig = &ChainConfig{big.NewInt(1), big.NewInt(0), nil, false, big.NewInt(0), common.Hash{}, big.NewInt(0), big.NewInt(0), big.NewInt(0), nil, new(EthashConfig), nil, nil}
 	TestRules       = TestChainConfig.Rules(new(big.Int))