Eval lib, modules, and overlays

Fixes #2

.travis.yml

@@ -14,8 +14,10 @@ install:
  - if [ -n "${CACHIX_CACHE}" ]; then cachix use "${CACHIX_CACHE}"; fi
 
 script:
- - outs=$(nix-build non-broken.nix)
- - echo Produced $outs
+ - outs=$(nix-build non-broken.nix) && echo Produced $outs
+ - nix eval -f default.nix 'lib'
+ - nix eval -f default.nix 'modules'
+ - nix eval -f default.nix 'lib'
 
 after_success:
   - if [ -n "${CACHIX_CACHE}" ]; then cachix push "${CACHIX_CACHE}" $outs; fi