Update client file with code style used in other files and add editorconfig

.editorconfig

+root = true
+
+[*.js]
+indent_style = space
+end_of_line = lf
+indent_size = 2
+charset = utf-8
+trim_trailing_whitespace = true
+insert_final_newline = true
+
+[*.md]
+trim_trailing_whitespace = false

lib/client.js

@@ -13,7 +13,7 @@ var ALLOWED_CREDENTIALS = [
  * make a basic request
  * @param url
  * @param apiKey
- * @param method :  [ GET, POSt, PUT ...]
+ * @param method :  [ GET, POST, PUT ...]
  * @param body
  * @param callback  (err, httpResponse, body)
  */
@@ -52,7 +52,7 @@ var basicRequest = function (url, apiKey, method, body, callback) {
  * @returns {boolean}
  */
 var checkCredential = function (credentialName, credential) {
-	for (var i = 0; i < ALLOWED_CREDENTIALS.length; i++) {
+	for (var i = 0, credentialLen = ALLOWED_CREDENTIALS.length; i < credentialLen; i++) {
 		if (ALLOWED_CREDENTIALS[i].name === credentialName) {
 			if (typeof credential !== ALLOWED_CREDENTIALS[i].type) {
 				throw credentialName + ' must be a ' + ALLOWED_CREDENTIALS[i].type;
@@ -127,7 +127,6 @@ Client.prototype.sendNotification = function (notification, callback) {
 	} else {
 		throw 'You must set either an "app" or "apps" on Client';
 	}
-	
 };
 
 /**
@@ -308,5 +307,4 @@ Client.prototype.csvExport = function (body, callback) {
 	return basicRequest(csvUri, this.app.appAuthKey, 'POST', body, callback);
 };
 
-
 module.exports = Client;