Tester abstract class

Abstract_tester.js

class Tester {

  constructor () {
    if (new.target === Tester) {
      throw new TypeError("Cannot construct Tester instances directly");
    }
  }
  
  execLintCommand () {
    //return a promise will executing 
    // this.lintCommand added in childrens class
  }
  
  execRunCommand () {
    //return a promise will executing 
    // this.runCommand added in childrens class
  }
  
  [...]

}