v0.5.0

Breaking changes:

• Bumped minimum PHP version from 5.4 to 5.6 (#220)
• #214 parse an img element for src and alt — i.e. all property values parsed as image URLs where the img element has an alt attribute will now be a {'value': 'url', 'alt': 'the alt value'} structure rather than a single URL string
• Renamed master branch to main. Anyone who had been installing the latest development version with dev-master will need to change their requirements to dev-main

Other changes:

• #195 Fix backcompat parsing for geo property
• #182 Fix parsing for iframe.u-*[src]
• #206 Add optional ID for h-* elements
• #198 reduce instances where photo is implied
• Internal: switched from Travis to Github Actions for CI