a failing test to reproduce #33

It's strange that something in the dependency graph turns on
serde automatically there, even though that doesn't happen
when compiling with the crate as dependency.

Author: Byron

.github/workflows/ci.yml

@@ -17,4 +17,11 @@ jobs:
       run: make test
     - name: docs
       run: cargo doc
+    - name: usage as dependency
+      run: |
+          cargo init user
+          cd user
+          cargo add --path ..
+          cargo check
+