5 pipeline with unit tests (#10)

---------

Co-authored-by: Julian Piribauer <julian.piribauer@gmail.com>
Co-authored-by: julian <julian.piribauer@gmail.com>
Reviewed-on: #10

.gitea/preparse.sh

@@ -0,0 +1,26 @@
+#!/usr/bin/env bash
+
+# This script is run in the CI container to preparse all .sage files into .sage.py files
+# and can also be run locally for local linting/testing.
+
+set -e
+
+if command -v python >/dev/null 2>&1 && python -c "import sage.repl" >/dev/null 2>&1; then
+  run_python() { python "$@"; }
+else
+  run_python() { sage --python "$@"; }
+fi
+
+for f in $(find . -name "*.sage" -not -path "./playground/*"); do
+  run_python -c "
+import sys
+from sage.repl.preparse import preparse_file
+
+path = sys.argv[1]
+with open(path) as fh:
+    src = fh.read()
+with open(path + '.py', 'w') as fh:
+    fh.write('from sage.all import *  # noqa: F401,F403\n')
+    fh.write(preparse_file(src))
+" "$f"
+done