test,CI: put Travis script in `tools/`

This is a first step towards #17.
build,doc: put doc-building functions in `tools/`

This is also related to #17.
build: put put/remove -license in `tools/`

The file in `tools/` is (again) an environment file that is sourced on a
need basis by `./please.sh`.
This is related to #17.
build,test: put test-env functions in `tools/`

This is also related to #17.
build: put the crazy ocp-build hacks in `tools/`

This also contributes to #17.