feat(replace): register replace task as a more specific task

replace object has only one key:
    replace: {
      dist: {
        src: ['app/*.vm'],
        dest: '.tmp/',
        replacements: loadReplacements()
      }
    },


The purpose of this fix is to make the replace command more specific. 

This will enable me to add more replace commands and register them without colliding with replace:dist command (it is required in the wix-styles project)