enable the use of an array for webpack config (multiple configs)
enable the use of an array for webpack config (multiple configs)

* split main webpackTask into two parts (webpackTask and setupConfig)
 * setupConfig takes a single config and appends the plugins as previous
 * webpackTask feeds the  setupConfig function with each single config

ipunkt/docker-gulp-tasks,ipunkt/docker-gulp-tasks,piJoe/docker-gulp-tasks,ipunkt/docker-gulp-tasks,piJoe/docker-gulp-tasks,piJoe/docker-gulp-tasks