Automatically determine version from build info or git

snikket_web/_version.py

@@ -1,5 +1,15 @@
-version_info = (0, 2, 1, None)
-version = (
-    ".".join(map(str, version_info[:3])) +
-    (f"-{version_info[3]}" if version_info[3] else "")
-)
+import os
+import subprocess
+
+version = "(unknown)"
+
+if os.path.exists(".app_version"):
+    with open(".app_version") as f:
+        version = f.read().strip()
+elif os.path.exists(".git"):
+    try:
+        version = subprocess.check_output([
+            "git", "describe", "--always"
+        ]).strip().decode("utf8")
+    except OSError:
+        version = "dev (unknown)"