Merge pull request #71 from sigmavirus24/master

Update README for testing instructions
Use pkg_resources to load registered commands

Closes #32
Fix tests after switching to pkg_resources
Add test for upload functionality
Merge pull request #72 from sigmavirus24/bug/32

Use pkg_resources to load registered commands
List registered commands in help text

Fixes #34
Closes #54
Merge pull request #73 from sigmavirus24/bug/34

List registered commands in help text
Try to prevent the occasional ResourceWarning
Merge pull request #75 from sigmavirus24/bug/28

Try to prevent the occasional ResourceWarning