Merge branch 'develop' of https://github.com/stac-utils/pystac into set_property

# Conflicts:
#	pystac/extensions/projection.py

Author: volaya

CHANGELOG.md

@@ -5,6 +5,7 @@
 ### Fixed
 
 - Fix handling of optional properties when using apply on view extension ([#259](https://github.com/stac-utils/pystac/pull/259))
+- Fixed issue with setting None into projection extension fields that are not required breaking validation ([#269](https://github.com/stac-utils/pystac/pull/269))
 
 ### Changed
 

tests/extensions/test_projection.py

@@ -97,6 +97,14 @@ def test_apply(self):
             shape=[100, 100],
             transform=[30.0, 0.0, 224985.0, 0.0, -30.0, 6790215.0, 0.0, 0.0, 1.0])
 
+    def test_partial_apply(self):
+        proj_item = pystac.read_file(self.example_uri)
+
+        proj_item.ext.projection.apply(epsg=1111)
+
+        self.assertEqual(proj_item.ext.projection.epsg, 1111)
+        proj_item.validate()
+
     def test_validate_proj(self):
         item = pystac.read_file(self.example_uri)
         item.validate()