Update CHANGELOG with many to many field handling

CHANGELOG.md

@@ -3,6 +3,10 @@
 * Add `--include-migrations-from` option to only consider migrations specified in a given file.
 No matter if the migrations are selected from a git commit or not, we only select the ones in the given file.
 
+Fixed bugs:
+
+* Handle adding many to many fields correctly.
+
 ## 1.3.0
 
 * Add `--exclude-migration-tests` option to ignore backward incompatible migration tests.