diff --git a/.travis.yml b/.travis.yml
index ab9b2f78..6b2fe7ab 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -50,6 +50,8 @@ matrix:
 deploy:
   provider: pypi
   user: betatim
+  # this line together with `setup.cfg` creates universal wheels as long as
+  # repo2docker is a python only module (no compiled code)
   distributions: sdist bdist_wheel
   on:
     tags: true
diff --git a/repo2docker/__init__.py b/repo2docker/__init__.py
index 7fd229a3..2b8877c5 100644
--- a/repo2docker/__init__.py
+++ b/repo2docker/__init__.py
@@ -1 +1 @@
-__version__ = '0.2.0'
+__version__ = '0.5.0'
diff --git a/setup.cfg b/setup.cfg
index 947f15f2..e794c7df 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -1,5 +1,8 @@
+# used by our travis auto-deployment system
+# needs changing if repo2docker ever stops being
+# a pure python module
 [wheel]
-universal=1
+universal = 1
 
 [metadata]
 license_file = LICENSE
diff --git a/setup.py b/setup.py
index f8fe5fdd..3a348a60 100644
--- a/setup.py
+++ b/setup.py
@@ -2,7 +2,7 @@ from setuptools import setup, find_packages
 
 setup(
     name='jupyter-repo2docker',
-    version='0.5.0',
+    version='0.5.1',
     install_requires=[
         'docker',
         'traitlets',