Lazyload images
Test images get inserted
We don't care if browsers have JS activated if they do not Cut the Mustard
Merge branch 'master' of github.com:guardian/frontend into trail-images-optimisation
Image upgrade conditions are prettier
Test insertion of lowres images on small screens and low bandwidths
Merge branch 'master' of github.com:guardian/frontend into trail-images-optimisation
Image tests are now more robust

Essentially they were passing and failing at different viewports.
Merge branch 'master' of github.com:guardian/frontend into trail-images-optimisation
Replace src only if image has a lowsrc or a fullsrc data attribute
Related content lazy loaded gets images
Merge pull request #1089 from guardian/trail-images-optimisation

Lazy load images in trails