allow for plugins without packages

Author: tomvanmele

src/compas_rhino/install.py

@@ -187,7 +187,7 @@ def install(version=None, packages=None, clean=False):
 
     # output the outcome of the installation process
     # perhaps we should more info here
-    print('Installing COMPAS packages to Rhino {0} scripts folder:'.format(version))
+    print('\nInstalling COMPAS packages to Rhino {0} scripts folder:'.format(version))
     print('{}\n'.format(scripts_path))
 
     for package, status in results:

src/compas_rhino/install_plugin.py

@@ -125,9 +125,6 @@ def install_plugin(plugin, version=None):
     if not __plugin__.title:
         raise Exception('Plugin title is not set.')
 
-    if not __plugin__.packages:
-        raise Exception('Plugin packages is not set.')
-
     plugin_fullname = "{}{}".format(__plugin__.title, __plugin__.id)
 
     python_plugins_path = compas_rhino._get_rhino_pythonplugins_path(version)
@@ -140,7 +137,8 @@ def install_plugin(plugin, version=None):
 
     # Stat the installation process
 
-    install_packages(version=version, packages=__plugin__.packages)
+    if hasattr(__plugin__, 'packages'):
+        install_packages(version=version, packages=__plugin__.packages)
 
     print('\nInstalling PlugIn {} to Rhino PythonPlugIns.'.format(plugin_name))