Update item.py

Minor edits for redundancy

Author: RichardScottOZ

pystac/item.py

@@ -941,7 +941,7 @@ def get_created(self, asset=None):
 
         Note:
             ``created`` and ``updated`` have different meaning depending on where they are used.
-            If those fields are available in the Item `properties`, it's referencing to the
+            If those fields are available in the Item `properties`, it's referencing the
             creation and update times of the metadata. Having those fields in the Item `assets`
             refers to the creation and update times of the actual data linked to
             in the Asset Object.
@@ -978,7 +978,7 @@ def updated(self):
 
         Note:
             ``created`` and ``updated`` have different meaning depending on where they are used.
-            If those fields are available in the Item `properties`, it's referencing to the
+            If those fields are available in the Item `properties`, it's referencing the
             creation and update times of the metadata. Having those fields in the Item `assets`
             refers to the creation and update times of the actual data linked to
             in the Asset Object.
@@ -1002,7 +1002,7 @@ def get_updated(self, asset=None):
 
         Note:
             ``created`` and ``updated`` have different meaning depending on where they are used.
-            If those fields are available in the Item `properties`, it's referencing to the
+            If those fields are available in the Item `properties`, it's referencing the
             creation and update times of the metadata. Having those fields in the Item `assets`
             refers to the creation and update times of the actual data linked to
             in the Asset Object.