Clarify elementCount arguments

Before this commit the term `selector` was used for two separate arguments in two separate scopes. Rename the function passed to the browser so the developer understands that these are two arguments/two scopes/not the same value.

Author: robwierzbowski

template/test/e2e/custom-assertions/elementCount.js

@@ -18,8 +18,8 @@ exports.assertion = function (selector, count) {
  }
  this.command = function (cb) {
  var self = this{{#if_eq lintConfig "airbnb"}};{{/if_eq}}
- return this.api.execute(function (selector) {
- return document.querySelectorAll(selector).length{{#if_eq lintConfig "airbnb"}};{{/if_eq}}
+ return this.api.execute(function (selectorToCount) {
+ return document.querySelectorAll(selectorToCount).length{{#if_eq lintConfig "airbnb"}};{{/if_eq}}
  }, [selector], function (res) {
  cb.call(self, res){{#if_eq lintConfig "airbnb"}};{{/if_eq}}
  }){{#if_eq lintConfig "airbnb"}};{{/if_eq}}