message: Update Creating-an-SDK-Client.md
  fixed typo in name of config variable passed to PartnerApplication and PublicApplication methods
diff: @@ -89,7 +89,7 @@ var config = require('/some/path/to/config.js');
  if (config.privateKeyPath && !config.privateKey)
  config.privateKey = fs.readFileSync(config.privateKeyPath);
  -var xeroClient = new xero.PublicApplication(myConfigFile);
  +var xeroClient = new xero.PublicApplication(config);
  ```
  ## Partner Usage
  @@ -103,7 +103,7 @@ var config = require('/some/path/to/config.js');
  if (config.privateKeyPath && !config.privateKey)
  config.privateKey = fs.readFileSync(config.privateKeyPath);
  -var xeroClient = new xero.PartnerApplication(myConfigFile);
  +var xeroClient = new xero.PartnerApplication(config);
  ```
  Now that you've got your Xero client, you can make some calls!
  