Merge pull request davidbyttow#170 from davidbyttow/gobject_save

Uses libvips operation API for saving

Merge pull request davidbyttow#151 from davidbyttow/export_params

Adds format-specific export params

Proper temporary files, remove hardcoded paths

Replace CI test console logging with TestMain

Merge pull request davidbyttow#137 from vansante/revert-buffer

Revert "Avoid allocating a new go byte slice buffer and instead reuse the C buffer"

Fix bug reported in issue davidbyttow#124

Merge pull request davidbyttow#114 from joomcode/feature/add-gc-support

Add GC support for `vips.ImageRef`

Fix dependency instructions for macOS

Update to version 2.0.0

Minor fixes