Bump dependencies to build with GHC 7.8.

Signed-off-by: Magnus Therning <magnus@therning.org>
Add license headers to all Data.Conduit.* files.

Better late than never.

Signed-off-by: Magnus Therning <magnus@therning.org>
Use tasty for testing.

Signed-off-by: Magnus Therning <magnus@therning.org>