plugins: fix loading of catkin-tools (#3168)

Typo "catkin_tools" should be "catkin-tools".

We need a spread test for this plugin.

LP: #1882996

Signed-off-by: Chris Patterson <chris.patterson@canonical.com>

Author: Chris Patterson

snapcraft/plugins/_plugin_finder.py

@@ -29,7 +29,7 @@
             "ant": v1.AntPlugin,
             "autotools": v1.AutotoolsPlugin,
             "catkin": v1.CatkinPlugin,
-            "catkin_tools": v1.CatkinToolsPlugin,
+            "catkin-tools": v1.CatkinToolsPlugin,
             "cmake": v1.CMakePlugin,
             "colcon": v1.ColconPlugin,
             "conda": v1.CondaPlugin,