Merge tag '0.2.0' into develop

Version 0.2.0
Update README

Signed-off-by: Tim Smart <tim.smart@designworks.co.nz>
Better width and height events

raf made them quite slow. We were also forgetting to set the working switch to
false

Signed-off-by: Tim Smart <tim.smart@designworks.co.nz>
Bump version to 0.2.1

Signed-off-by: Tim Smart <tim.smart@designworks.co.nz>
Merge branch 'release/0.2.1'