taking screenshots with casperjs adds transparent background

[Isger Janson]

Running wraith capture configs/capture.yaml will yield image results that totally differ because of an added transparent background.

The original screenshots taking and saved in /shots are partially ok with one set of images all fine (in this case domain 'new') and the other set ('current') with added transparent background.

I'm using casperjs with selector: '' because taking screenshots on my websites with phantomjs ignores the viewport.

$ convert --version
Version: ImageMagick 7.0.6-10 Q16 x86_64 2017-08-28 http://www.imagemagick.org
Copyright: © 1999-2017 ImageMagick Studio LLC
License: http://www.imagemagick.org/script/license.php
Features: Cipher DPC HDRI Modules 
Delegates (built-in): bzlib freetype jng jpeg ltdl lzma png tiff xml zlib

---
browser: "casperjs"

domains:
  current: "https://www.url.com"
  new: "http://www.url.de/"

paths:
  home:
    path: /
    selector: ''

screen_widths:
  - 320x5000
  - 600x5000
  - 768x5000
  - 1024x5000
  - 1280x5000

directory: 'shots'

fuzz: '20%'

threshold: 5

gallery:
  template: 'slideshow_template'
  thumb_width: 200
  thumb_height: 200

mode: diffs_first

before_capture: 'javascript/wait--casper.js'

resize_or_reload: 'resize'

verbose: true