Merge branch 'upgrade'
set host for jpegoptim
ignore tmp dir
remove ruby-head and jruby-head from travis
run rubocop in separate worker and join scripts into one
config jpeg-archive
build jpeg-recompress
add livecheck for jpegarchive and libmozjpeg
Merge branch 'jpeg-archive'
depend on image_optim ~> 0.19
v0.2.0
Merge tag 'v0.2.0' into update
pngcrush 1.7.80
pngcrush 1.7.81
libpng 1.6.15