Merge pull request #41 from pepkit/dev

v0.4.0

Merge pull request #39 from pepkit/dev

v0.3.2

Merge pull request #38 from pepkit/dev

v0.3.1

Merge pull request #36 from pepkit/dev

v0.3.0

Merge pull request #34 from pepkit/dev

v0.2.2

Merge pull request #27 from pepkit/dev

Release 0.2

Merge pull request #26 from pepkit/dev

v0.1

Merge pull request #11 from pepkit/dev

Release 0.0.4

Update README.md

#9

Fix several bugs:

- handling relative pipeline interfaces
- handling null metadata attributes