[Author] Updated to v1.3.1

Updated to v1.3.1, with major changes since v1.2.4. More importantly,
desandro’s imagesLoaded plugin is no longer required. Multiple bug
fixes have also been implemented, with optimisation of code
organisation.
[Author] Updated to v1.3.1

Bug fixes and major code cleanup.
Updated package.json

Fixing build failures.
Merge pull request #3225 from terrymun/master

[author] Updated Fluidbox to v1.3.1