add ext interface

Author: wanwiset25

internal/web3ext/web3ext.go

@@ -490,6 +490,11 @@ web3._extend({
 			call: 'eth_getRewardByHash',
 			params: 1
 		}),
+		new web3._extend.Method({
+			name: 'getReceiptProof',
+			call: 'eth_getReceiptProof',
+			params: 1
+		}),
 		new web3._extend.Method({
 			name: 'getRawTransactionFromBlock',
 			call: function(args) {