Bump version to 1.3.1

Author: benoitc

CHANGELOG.md

@@ -1,5 +1,12 @@
 # Changelog
 
+## 1.3.1 (2026-02-16)
+
+### Fixed
+
+- **Hex.pm packaging** - Added `files` section to app.src to include build scripts
+  (`do_cmake.sh`, `do_build.sh`) and other necessary files in the hex.pm package
+
 ## 1.3.0 (2026-02-16)
 
 ### Added

src/erlang_python.app.src

@@ -1,6 +1,6 @@
 {application, erlang_python, [
     {description, "Execute Python applications from Erlang using dirty NIFs"},
-    {vsn, "1.3.0"},
+    {vsn, "1.3.1"},
     {registered, [py_pool]},
     {mod, {erlang_python_app, []}},
     {applications, [