Merge pull request #672 from JHKru/master

Docstrings for 'set_annotation': Remove 'None' as input type for 'array'.

Author: padix-key

src/biotite/structure/atoms.py

@@ -157,7 +157,7 @@ def set_annotation(self, category, array):
         ----------
         category : str
             The annotation category to be set.
-        array : ndarray or None
+        array : ndarray
             The new value of the annotation category. The size of the
             array must be the same as the array length.