make estimateGas optional

package.json

@@ -1,6 +1,6 @@
 {
   "name": "tx-manager",
-  "version": "0.1.0",
+  "version": "0.1.1",
   "description": "",
   "main": "index.js",
   "scripts": {

src/Transaction.js

@@ -111,10 +111,12 @@ class Transaction {
    * @private
    */
   async _prepare() {
+    if (!this.tx.gas || this.config.ESTIMATE_GAS) {
       const gas = await this._web3.eth.estimateGas(this.tx)
       if (!this.tx.gas) {
         this.tx.gas = Math.floor(gas * 1.1)
       }
+    }
     if (!this.tx.gasPrice) {
       this.tx.gasPrice = await this._getGasPrice('fast')
     }

src/TxManager.js

@@ -11,6 +11,7 @@ const defaultConfig = {
   MAX_GAS_PRICE: 1000,
   POLL_INTERVAL: 5000,
   CONFIRMATIONS: 8,
+  ESTIMATE_GAS: true,
 }
 
 class TxManager {