Pin stable compiletest to 0.3.18

Author: Manishearth

Cargo.toml

@@ -47,7 +47,7 @@ rustc_tools_util = { version = "0.1.1", path = "rustc_tools_util"}
 [dev-dependencies]
 clippy_dev = { version = "0.0.1", path = "clippy_dev" }
 cargo_metadata = "0.7.1"
-compiletest_rs = "0.3.18"
+compiletest_rs = "=0.3.18"
 lazy_static = "1.0"
 serde_derive = "1.0"
 clippy-mini-macro-test = { version = "0.2", path = "mini-macro" }