Don't need to recurse submodules anymore since we got rid of them.
Also remove the empty `.gitmodules` file.

We use our own version of rt now (for quite some time, actually).

We build it ourselves before running the tests.

Instead just load the rt files as a module in oct/tests system.

This fixes an issue where rt.asd was interfering with quicklisp.

It's :if-does-not-exist!

Check if quicklisp dir exists first before loading quicklisp.lisp.

Can't directly call quicklisp-quickstart:install because it's not
available yet when reading the file.

Download quicklisp.lisp file and install it, if we don't have
quicklisp already installed.

Load quicklisp.lisp if it exists and install it so we have quicklisp
available.  Needed for building.

First, minor fix is we don't need GIT_SUBMODULE_STRATEGY in .gitlab-ci
anymore because we got rid of the submodule.

Important change is in run-test where we load up quicklisp so that we
can get named-readtables.

The latest version of quicklisp has the version we want, so we don't
need our own copy.

Update asd file to require named-readtables from quicklisp.

We want to see the expected value when the test signals an error so we
can easily test implementations against the expected value.
Previously, we'd have to look at the data files to find the expected
value.

Rename the functions to make it clearer what's being computed since
we're using -upper and -lower for the different parts of the
incomplete gamma function.  So:

- `cf-incomplete-gamma-tail` -> `cf-incomplete-gamma-upper`
- `cf-incomplete-gamma` -> `cf-incomplete-gamma-lower`
- `s-incomplete-gamma` -> `s-incomplete-gamma-lower`

Fix #18: Add more tests incomplete gamma

Closes #18

See merge request !19

Add more tests using the data provided in
#9 (comment 7019).

We first need convert the original test data into a form that we can
read by converting the numbers to #q form.

The distance between erf/erfc and the arg is too small.  Make it a
little bigger.

Fix #20: Support sbcl better

Closes #20

See merge request !18

- Fix typo: extra closing paren
- Add new failing tests: oct.elliptic-pi.n0.q gamma.3.q
- Change a few tests so that the test result on failure includes the
  actual argument used for the gamma function.

- Use a fixed known `*random-state*` for sbcl.
- Fix warning about unused variable.

Address #14: More refactoring

See merge request !17

Move all the internal implementation details to the internals
directory so we can see quickly what is internal and what is not.

Fix #19: Add more API documentation

Closes #19

See merge request !16

Break the API docs into sections for related functions based on the
chapters from the [DLMF](https://dlmf.nist.gov).  Give definitions
(and possibly links) for the functions.

Messes up the link.

Fix #9: Implement normalized incomplete gamma functions

Closes #9

See merge request !13

Adds two new functions:

- incomplete-gamma-upper-normalized
- incomplete-gamma-lower-normalized

These are the corresponding incomplete gamma functions but normalized
by gamma(a).

Fix #17: Update README

Closes #17

See merge request !15

Copied the main items from the wiki page, including the intro,
building, and using.

Fix #16: Use named-readtables

Closes #16

See merge request !14

This way we can run `(asdf:test-system :oct)` as many times as we want
and get consistent results.

This needs work for other lisps.