Add `Ord` instances for capability types

See merge request !15

cannot re-pack a thunk with unknown files in it
these files are known and are not meant to be committed

add ConfidentialShowable instances and deprecate dangerRealShow

See merge request !14

Auto generate cabal project

See merge request !13

drop the base constraint from the cabal test target

Closes #8

See merge request !12

Presumably we still have some lower bound but I don't know what it is and if
it's below 8.6.5 ... it doesn't matter to anyone that _I_ know of.

Release 0.2.0.0

See merge request !11

expose random IV generation in the public interface

See merge request !10

we'll also run the tests after which is great, but this at least gets us some
automatic checking of our executables which aren't really covered by automated
tests

callers of the encode interface are now required to pass in the correct iv for
the ciphertext being encoded

Parse and serialize SDMF capabilities

Closes #1

See merge request !8

Remove all of the GitLab cache configuration

See merge request !9

The cache periodically becomes corrupt and causes builds to fail.

Plus various basic instances (Eq, Show, mainly) to make testing this piece
easier.

Also some more Hedgehog generators for types related to capabilities.

Also scatter some more Eq and Show instances around to make this possible.
Also change some Show instances to elide most of the content of secrets.

Implement enough encryption and encoding to be able to read plaintext from Tahoe-LAFS-generated SDMF shares

Closes #5

See merge request !7

This functionality moved in to readShareFromBucket

We need a lot of type conversions and we'd like to be more principled than
`fromIntegral`.