chore: remove deprecated image.ZP

fix: avoid creating a new endpoint in prometheus for each urls

feat: add open with stat (thoas#176)

chore: go mod tidy

ref: use logger in every environments

feat: add gifsicle backend (thoas#134)

docs: README

Go modules support

Merge pull request thoas#99 from thoas/refac-engine-config

Refac engine config

feat: use ca-certificates from alpine