v0.20.6 - 20th August 2018

Add removeAlpha operation to remove alpha channel, if any. #1248

Expose mozjpeg quant_table flag. #1285 @rexxars

Allow full WebP alphaQuality range of 0-100. #1290 @sylvaindumont

Cache libvips binaries to reduce re-install time. #1301

Ensure vendor platform mismatch throws error at install time. #1303

Improve install time error messages for FreeBSD users. #1310

Ensure extractChannel works with 16-bit images. #1330

Expose depth option for tile-based output. #1342 @alundavies

Add experimental entropy field to stats response.