Remove spurious trailing space

This fixes issue #165.

pglast/printers/ddl.py

@@ -1330,8 +1330,9 @@ def CONSTR_IDENTITY(self, node, output):
             output.write('ALWAYS ')
         elif node.generated_when == enums.ATTRIBUTE_IDENTITY_BY_DEFAULT:
             output.write('BY DEFAULT ')
-        output.write('AS IDENTITY ')
+        output.write('AS IDENTITY')
         if node.options:
+            output.space()
             with output.expression(True):
                 output.print_list(node.options, '')
 
@@ -1403,7 +1404,7 @@ def constraint(node, output):
             output.write(' USING INDEX TABLESPACE ')
             output.print_name(node.indexspace)
         if node.skip_validation:
-            output.write(' NOT VALID ')
+            output.write(' NOT VALID')
 
 
 @node_printer(ast.CreateAmStmt)

tests/test_printers_prettification/ddl/alter_table.sql

@@ -1,3 +1,17 @@
 ALTER TABLE tab1 ADD CONSTRAINT foo FOREIGN KEY (id1) REFERENCES tab2 (id2) DEFERRABLE INITIALLY DEFERRED
 =
 ALTER TABLE tab1 ADD CONSTRAINT foo FOREIGN KEY (id1) REFERENCES tab2 (id2) DEFERRABLE INITIALLY DEFERRED
+
+ALTER TABLE color ALTER COLUMN color_id ADD GENERATED BY DEFAULT AS IDENTITY
+=
+ALTER TABLE color ALTER COLUMN color_id ADD GENERATED BY DEFAULT AS IDENTITY;
+:
+{'semicolon_after_last_statement': True}
+
+ALTER TABLE books
+ADD CONSTRAINT distfk
+FOREIGN KEY (author_id) REFERENCES authors (author_id) ON UPDATE RESTRICT NOT VALID
+=
+ALTER TABLE books ADD CONSTRAINT distfk FOREIGN KEY (author_id) REFERENCES authors (author_id) ON UPDATE RESTRICT NOT VALID;
+:
+{'semicolon_after_last_statement': True}