Migrate from Dep to Go Modules
Go Modules are the preferred way to manage dependencies in Go programs
since version 1.11. The migration process involves:
1. go mod init git.dominic-ricottone.com/~dricottone/image2ascii
(replace the host as needed)
2. Replace the host in files requiring an internal module
(this was specifically image2ascii.go, convert/convert.go,
convert/resize.go, and convert/resize_test.go)
3. go mod tidy
4. rm -rf vendor/ Gopkg.lock Gopkg.toml
5. go get -u
go.mod now contains all the information required to build the program.