updates + refactor

[elithrar]

updates:

• we should be a go module
• remove TravisCI and replace with a GitHub Action workflow that runs our tests across a matrix of Go versions (https://go.dev/doc/devel/release) - for us, 1.20 and above.
• remove the old TravisCI README badge.

[elithrar]

/bonk action this

[ask-bonk]

To https://github.com/elithrar/simple-scrypt
! [remote rejected] opencode/issue24-20251225155524 -> opencode/issue24-20251225155524 (refusing to allow a GitHub App to create or update workflow .github/workflows/test.yml without workflows permission)
error: failed to push some refs to 'https://github.com/elithrar/simple-scrypt'

opencode session  |  github run

[elithrar]

/bonk make the Go changes as a PR and include the new test workflow as a code block in the PR desc for me to action manually

[ask-bonk]

Created PR #25

opencode session  |  github run