added the configuration to test Sokol-to-Ropsten bridge with gas price oracle

erc20/bridge/sokol_ropsten_config_rpc_gasprice.toml

@@ -0,0 +1,35 @@
+keystore = "./keys"
+
+[home]
+account = "0xd6d713a71eb3955c680d5967e9bb22298edefcc3"
+required_confirmations = 1
+poll_interval = 5
+request_timeout = 60
+rpc_host = "https://sokol.poa.network"
+rpc_port = 443
+password = "./keys/d6d713a71eb3955c680d5967e9bb22298edefcc3.pwd"
+default_gas_price = 1000000000
+
+[foreign]
+account = "0xd6d713a71eb3955c680d5967e9bb22298edefcc3"
+required_confirmations = 8
+poll_interval = 15
+request_timeout = 60
+rpc_host = "https://ropsten.infura.io/vB2QHsRyOrw15sBk6MUL"
+rpc_port = 443
+password = "./keys/d6d713a71eb3955c680d5967e9bb22298edefcc3.pwd"
+default_gas_price = 21000000000
+gas_price_oracle_url = "https://gasprice.poa.network/"
+gas_price_speed = "fast"
+gas_price_timeout = 10
+
+[authorities]
+accounts = [
+        "0xd6d713a71eb3955c680d5967e9bb22298edefcc3"
+]
+required_signatures = 1
+
+[transactions]
+deposit_relay = { gas = 120000, concurrency = 100 }
+withdraw_confirm = { gas = 300000, concurrency = 100 }
+withdraw_relay = { gas = 300000, concurrency = 100 }