Delete macro expand tests

So far I haven't ended up being that pleased with the value proposition
of these tests.

test_suite/Cargo.toml

@@ -18,8 +18,6 @@ toolchain_find = "0.2"
 
 [dev-dependencies]
 fnv = "1.0"
-macrotest = "=1.0.9"
-prettyplease = "=0.1.14"
 rustversion = "1.0"
 serde = { path = "../serde", features = ["rc", "derive"] }
 serde_derive = { path = "../serde_derive", features = ["deserialize_in_place"] }