isRegExp (value) {
    return toStr(value) === REGEXP_TAG
  }
Return whether the provided value is a regular expression.

@example
import { utils } from 'js-data';
const a = /^\$.+$/ig;
const b = new RegExp('^\$.+$', 'ig');
const c = { foo: "bar" };
console.log(utils.isRegExp(a)); // true
console.log(utils.isRegExp(b)); // true
console.log(utils.isRegExp(c)); // false

@method utils.isRegExp
@param {*} value The value to test.
@returns {boolean} Whether the provided value is a regular expression.
@since 3.0.0