SG-38813 Update supported versions (#80)

* Mark 18.5 as the oldest compatible version

* Update badges

Author: julien-lang

README.md

@@ -1,5 +1,9 @@
-[![VFX Platform](https://img.shields.io/badge/vfxplatform-2025%20%7C%202024%20%7C%202023%20%7C%202022-blue.svg)](http://www.vfxplatform.com/)
-[![Python](https://img.shields.io/badge/python-3.11%20%7C%203.10%20%7C%203.9-blue.svg)](https://www.python.org/)
+# Toolkit Engine for Houdini
+
+![Supported Houdini versions: 19.5 - 20.5](https://img.shields.io/badge/Houdini-20.5_|_20.0_|_19.5-blue?logo=houdini&logoColor=f5f5f5 "Support Maya versions")
+[![Supported VFX Platform: 2022 - 2025](https://img.shields.io/badge/VFX_Platform-2025_|_2024_|_2023_|_2022-blue)](http://www.vfxplatform.com/ "Supported VFX Platform")
+[![Supported Python versions: 3.9 - 3.11](https://img.shields.io/badge/Python-3.11_|_3.10_|_3.9-blue?logo=python&logoColor=f5f5f5)](https://www.python.org/ "Supported Python versions")
+
 [![Build Status](https://dev.azure.com/shotgun-ecosystem/Toolkit/_apis/build/status/Engines/tk-houdini?branchName=master)](https://dev.azure.com/shotgun-ecosystem/Toolkit/_build/latest?definitionId=63&branchName=master)
 [![Code style: black](https://img.shields.io/badge/code%20style-black-000000.svg)](https://github.com/psf/black)
 [![Linting](https://img.shields.io/badge/PEP8%20by-Hound%20CI-a873d1.svg)](https://houndci.com)

engine.py

@@ -66,10 +66,10 @@ def init_engine(self):
 
         self.logger.debug("%s: Initializing..." % self)
 
-        if self._houdini_version[0] < 14:
+        if self._houdini_version[0:2] < (18, 5):
             raise sgtk.TankError(
-                "Your version of Houdini is not supported. Currently, Toolkit "
-                "only supports version 14+."
+                "Flow Production Tracking is not compatible with Houdini "
+                "versions older than 18.5."
             )
 
         # keep track of if a UI exists

startup.py

@@ -69,7 +69,7 @@ class HoudiniLauncher(SoftwareLauncher):
     @property
     def minimum_supported_version(self):
         """The minimum supported Houdini version."""
-        return "14.0"
+        return "18.5"
 
     def prepare_launch(self, exec_path, args, file_to_open=None):
         """