feat!: Drop returns bool, Put doesn't stack-overflow (#21)

## Description

Closes #11.

## Changes

### Design Decisions

## Checklist

- [ ] Tests pass
- [ ] Docs updated

Reviewed-on: #21
Co-authored-by: M.V. Hutz <git@maximhutz.me>
Co-committed-by: M.V. Hutz <git@maximhutz.me>

cuckoo_fuzz_test.go

@@ -68,12 +68,13 @@ func FuzzInsertLookup(f *testing.F) {
 
 		for _, step := range scenario.steps {
 			if step.drop {
-				err := actual.Drop(step.key)
-				assert.NoError(err)
+				ok := actual.Drop(step.key)
+				_, has := expected[step.key]
+				assert.Equal(ok, has)
 
 				delete(expected, step.key)
 
-				_, ok := actual.Get(step.key)
+				_, ok = actual.Get(step.key)
 				assert.False(ok)
 			} else {
 				err := actual.Put(step.key, step.value)