fix webserver errors

lib/contracts/provider.js

@@ -58,6 +58,7 @@ class Provider {
 
     self.accounts = AccountParser.parseAccountsConfig(self.accountsConfig, self.web3, self.logger);
     self.addresses = [];
+
     if (!self.accounts.length) {
       return callback();
     }
@@ -75,20 +76,31 @@ class Provider {
       return new Promise((resolve, reject) => {
         self.realAccountFunction((err, accounts) => {
           if (err) {
-            cb(err);
-            return reject(err);
+            return cb(err);
           }
           accounts = accounts.concat(self.addresses);
           // accounts = self.addresses.concat(accounts);
           cb(null, accounts);
           resolve(accounts);
         });
-      });
+      }
+      realSend(payload, cb);
     };
 
     callback();
   }
 
+  stop() {
+    if (this.provider && this.provider.removeAllListeners) {
+      this.provider.removeAllListeners('connect');
+      this.provider.removeAllListeners('error');
+      this.provider.removeAllListeners('end');
+      this.provider.removeAllListeners('data');
+      this.provider.responseCallbacks = {};
+      this.provider = null;
+    }
+  }
+
   fundAccounts(callback) {
     const self = this;
     if (!self.accounts.length) {