fix linting issues

Author: pickypg

package/lib/compileFunctions.js

@@ -48,7 +48,7 @@ module.exports = {
           _.get(this, 'serverless.service.provider.environment'),
           funcObject.environment // eslint-disable-line comma-dangle
         ),
-        (value) => value.toString() // eslint-disable-line comma-dangle
+        value => value.toString() // eslint-disable-line comma-dangle
       );
 
       if (!_.size(funcTemplate.properties.environmentVariables)) {