Remove remaining dummy book structure

These tests are now all superseded by the new testsuite.

Author: ehuss

Cargo.lock

@@ -64,8 +64,6 @@ elasticlunr-rs = { version = "3.0.2", optional = true }
 ammonia = { version = "4.0.0", optional = true }
 
 [dev-dependencies]
-assert_cmd = "2.0.11"
-predicates = "3.0.3"
 select = "0.6.0"
 semver = "1.0.17"
 snapbox = { version = "0.6.21", features = ["diff", "dir", "term-svg", "regex", "json"] }