Forward-port release notes for v1.5.1

docs/source/releases/v1.5.1.rst

@@ -0,0 +1,12 @@
+=========================
+Oscar 1.5.1 release notes
+=========================
+
+:release: 2017-11-29
+
+This is Oscar 1.5.1, a bug fix release.
+
+Bug fixes
+=========
+
+* Fixed django-haystack dependency to allow using the latest version of Django Haystack.