fix: allow media query ranges (#137)

* Updating operators to accept new ones

* Adding new test cases

* Adding missing operator

Author: Antonio Laguna

lib/nodes/Operator.js

@@ -12,7 +12,7 @@ const { registerWalker } = require('../walker');
 
 const Node = require('./Node');
 
-const operators = ['+', '-', '/', '*', '%'];
+const operators = ['+', '-', '/', '*', '%', '=', '<=', '>=', '<', '>'];
 const operRegex = new RegExp(`([/|*}])`);
 
 class Operator extends Node {

test/fixtures/word.js

@@ -13,6 +13,9 @@ module.exports = {
   snapshot: [
     'bold italic 12px \t /3 \'Open Sans\', Arial, "Helvetica Neue", sans-serif',
     '(min-width: 700px) and (orientation: \\$landscape)',
+    '(width < 700px)',
+    '(width <= 700px)',
+    '(width >= 500px) and (width <= 1200px)',
     ' \\"word\\" \\s ',
     '--color',
     '-webkit-transition',