Setup an empty unit test suite for lib.functions

I've added a dependency so if lib.macros isn't working, we can skip
all the tests in lib.functions.  Therefore we can use lib.macros in
the test code.

cantedraw.asd

@@ -26,7 +26,7 @@
   :components ((:module "tests"
                 :components
                 ((:file "macros")
-                 ;; (:file "functions")
+                 (:file "functions")
                  ;; (:file "model")
                  ;; (:file "player")
                  ;; (:file "game")

tests/functions.lisp

@@ -0,0 +1,24 @@
+;;; functions.lisp - 2025-02-20
+
+;; Copyright (C) 2025 Aryadev Chavali
+
+;; This program is distributed in the hope that it will be useful, but WITHOUT
+;; ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+;; FOR A PARTICULAR PURPOSE.  See the GNU General Public License Version 2 for
+;; details.
+
+;; You may distribute and modify this code under the terms of the GNU General
+;; Public License Version 2, which you should have received a copy of along with
+;; this program.  If not, please go to <https://www.gnu.org/licenses/>.
+
+;;; Code:
+
+(defpackage cantedraw/tests/functions
+  (:use
+   :cl :parachute :cantedraw.lib.macros
+   :cantedraw.lib.functions))
+
+(in-package :cantedraw/tests/functions)
+
+(define-test function-test
+  :depends-on ((cantedraw/tests/macros macro-test)))

tests/main.lisp

@@ -21,4 +21,5 @@
 
 (define-test all
   :serial t
-  :depends-on ((cantedraw/tests/macros macro-test)))
+  :depends-on ((cantedraw/tests/macros macro-test)
+               (cantedraw/tests/functions function-test)))