title: how can Parametrize protractor-config file for different browsers and test suites
body: <p>I am running my Protractor Test from command <code>npm run e2e</code></p>
  
  <p>I want a way so that if I pass <code>npm run e2e firefox</code> then my test will get executed on Firefox browser.</p>
  
  <p>Or if I run <code>npm run e2e chrome</code> then it should run on chrome</p>
  
  <p>if I pass both <code>npm run e2e firefox chrome</code> then my test should run on both the browser in parallel.</p>
  
  <p>Is it possible to parametrize protractor config file?</p>
  
  <p>Similarly if I can pass test suite name via command and it should execute only  tests under that particular test suite.</p>
  
  <p>Here is my config file and this is what I want to achieve:  </p>
  
  <pre><code>`//var HtmlReporter = require('protractor-html-screenshot-reporter');
  
  exports.config = {
  
  allScriptsTimeout: 30000,
  //Add parameters for browser names
  params:{
    pass: {
        browserName : 'chrome',
        testSuitName : 'e2e/TestSuites/_BVT/*.js',
    }
   },  
  suites: {    
  //Define here List of Sanity Test Scenarios:
    BVT : testSuitName,   
  }, 
  // configure multiple browsers to run tests
  multiCapabilities: [
   shardTestFiles: true,
   maxInstances: 2   
  {'browserName': browserName}
  ],
  baseUrl: 'http://mytestUrl/',
   framework: 'jasmine2',
  jasmineNodeOpts: {
   defaultTimeoutInterval: 30000
  },  
  onPrepare: function() {  
  var jasmineReporters = require('jasmine-reporters');
  browser.driver.manage().window().maximize();
  return browser.getProcessedConfig().then(function(config) {   
    var browserName = config.capabilities.browserName;
    var junitReporter = new jasmineReporters.JUnitXmlReporter({
           consolidateAll: true,
           savePath: 'tests/test-results',            
           filePrefix: browserName + '-xmloutput',
           modifySuiteName: function(generatedSuiteName, suite) {             
               return browserName + '.' + generatedSuiteName;
           }              
       });
       jasmine.getEnv().addReporter(junitReporter);
    });    
  }, 
  resultJsonOutputFile: 'tests/test-results/output.json'    
  };`
  </code></pre>
  
  <p>Would appreciate any help on this.<br>
  Thanks in advance. </p>