Don't require modules that possibly don't exist

Author: oliversalzburg

lib/worker.js

@@ -1,7 +1,3 @@
-
-var git = require('strider-git/worker')
-var hg = require('strider-hg/worker')
-
 module.exports = {
   init: function (dirs, account, config, job, done) {
     return done(null, {
@@ -21,9 +17,11 @@ module.exports = {
       config.auth.password = ''
     }
     if (config.scm === 'git') {
+        var git = require('strider-git/worker')
         git.fetch(dest, config, job, context, done)
     }
     else {
+        var hg = require('strider-hg/worker')
         hg.fetch(dest, config, job, context, done)
     }
   }