fix STAC Item provider output (#238) (#260)

Author: tomkralidis

pygeometa/schemas/stac/__init__.py

@@ -106,7 +106,8 @@ def write(self, mcf: dict, stringify: str = True) -> Union[dict, str]:
             },
             'properties': {
                 'title': title[0],
-                'description': description[0]
+                'description': description[0],
+                'providers': []
             },
             'links': []
         }
@@ -123,7 +124,9 @@ def write(self, mcf: dict, stringify: str = True) -> Union[dict, str]:
         if 'revision' in mcf['identification']['dates']:
             stac_item['properties']['updated'] = mcf['identification']['dates']['revision']  # noqa
 
-        stac_item['properties']['providers'] = [{'name': mcf['contact']['pointOfContact']['organization']}]  # noqa
+        for value in mcf['contact'].values():
+            stac_item['properties']['providers'].append({
+                'name': value['organization']})
 
         for value in mcf['distribution'].values():
             title = get_charstring(value.get('title'), lang1, lang2)