Testo command line tool

[metafates]

This PR introduces an auxiliary command line tool for Testo featuring linter, suites explorer and runner. No external dependencies.

Usage:
  testo [command]

Available Commands:
  lint       Run testo linter
  run        Run testo suites
  suites     Show testo suites
  tags       Show project build tags
  version    Show testo version

Example:

testo lint ./...
# /Users/user/ozontech/testo/examples/06_errors/main_test.go:23: invalid signature: Test requires param Foo to be of type int, have string

testo run mypkg/Functional.TestFoo
testo suites -f "{{ .Package }}/{{ .Suite }}" | fzf