Re-enable botan test on macos

PR #42 / ef63ca7 wasn't needed.
The botan author has ensured that their library works on macos
just fine.

Closes #52

Author: est31

Diff for: Cargo.toml

@@ -34,6 +34,4 @@ features = ["x509-parser"]
 [dev-dependencies]
 openssl = "0.10"
 webpki = "0.21"
-
-[target.'cfg(not(target_os = "macos"))'.dev-dependencies]
 botan = { version = "0.8", features = ["vendored"] }

Diff for: tests/botan.rs

@@ -1,5 +1,3 @@
-#![cfg(not(target_os = "macos"))]
-
 extern crate botan;
 extern crate rcgen;