make Vizier kwargs keyword-only

Author: keflavich

astroquery/vizier/core.py

@@ -272,7 +272,7 @@ def get_catalogs_async(self, catalog, verbose=False, return_type='votable',
 
         return response
 
-    def query_object_async(self, object_name, catalog=None, radius=None,
+    def query_object_async(self, object_name, *, catalog=None, radius=None,
                            coordinate_frame=None, get_query_payload=False,
                            return_type='votable', cache=True):
         """
@@ -323,7 +323,7 @@ def query_object_async(self, object_name, catalog=None, radius=None,
             data=data_payload, timeout=self.TIMEOUT, cache=cache)
         return response
 
-    def query_region_async(self, coordinates, radius=None, inner_radius=None,
+    def query_region_async(self, coordinates, *, radius=None, inner_radius=None,
                            width=None, height=None, catalog=None,
                            get_query_payload=False, cache=True,
                            return_type='votable', column_filters={},
@@ -332,6 +332,8 @@ def query_region_async(self, coordinates, radius=None, inner_radius=None,
         Serves the same purpose as `query_region` but only
         returns the HTTP response rather than the parsed result.
 
+        At least one of `radius` or `width` must be specified.
+
         Parameters
         ----------
         coordinates : str, `astropy.coordinates` object, or `~astropy.table.Table`
@@ -454,7 +456,7 @@ def query_region_async(self, coordinates, radius=None, inner_radius=None,
             data=data_payload, timeout=self.TIMEOUT, cache=cache)
         return response
 
-    def query_constraints_async(self, catalog=None, return_type='votable',
+    def query_constraints_async(self, *, catalog=None, return_type='votable',
                                 cache=True, get_query_payload=False,
                                 **kwargs):
         """