Update Nix config and install test dependencies during build

Update niv sources and allow building with custom nixpkgs collection

Update niv sources

Add sourcehut build manifest

Add reproducible build config

Clarify licensing for sq and SRFI-180 implementation

Add build instructions for Nix users and update niv sources

Drop unnecessary TODO item from README

Added tag 0.2 for changeset 4530cd746a24

Version 0.2

Add nix-shell config and niv sources

Add tests

Fill in remaining type declarations

Improve input format heuristics

Separate outgoing JSON data by newlines

Fix a few small issues with sq vs. jq help and version flag handling

Use Mercurial for build version generation

Added tag 0.1 for changeset c77fc027ef98

Add release file

Add README and LICENSE