If you are on Linux, run go build -o $GOPATH/bin/tinifier tinifier.go
If you are on Windows, run go build -o %GOPATH%/bin/tinifier.exe tinifier.go
Create a file named .tinify_api_key one level above the working directory. This file should contain the tinify.com API key without a leading CR and/or LF.
Create two folders named files and compressed in the working folder.
Place all pictures which needs to be compressed, inside the files folder.