tupleconv: add tt `interval` type. #27

	---
	name: Tests

	on: [push, pull_request]

	jobs:
	tests:
	if: (github.event_name == 'push') \|\|
	(github.event_name == 'pull_request' &&
	github.event.pull_request.head.repo.full_name != github.repository)

	runs-on: ubuntu-22.04

	steps:
	- uses: actions/checkout@master

	- name: Setup Go
	uses: actions/setup-go@v2
	with:
	go-version: '1.19'

	- name: golangci-lint
	uses: golangci/golangci-lint-action@v3
	continue-on-error: true
	with:
	# The first run is for GitHub Actions error format.
	args: --config=golangci-lint.yml

	- name: golangci-lint
	uses: golangci/golangci-lint-action@v3
	with:
	# The second run is for human-readable error format with a file name
	# and a line number.
	args: --out-${NO_FUTURE}format colored-line-number --config=golangci-lint.yml

	- name: Unit tests
	run: \|
	go test -race ./...

Provide feedback