v1.0.18

Changes

v1.0.18 / 2017-12-22

• Merge pull request #216 from Bynder/master
• Merge pull request #208 from mikestead/feature/webp-lossless
• Remove go-debug usage
• refactor(docs): remove codesponsor :(
• fix(options): use float64 type in Options.Threshold
• Merge pull request #206 from tstm/add-trim-options
• Add lossless option for saving webp
• Set the test file to write its own file
• Add the option to use background and threshold options on trim