Make wiremock an optional dependency

Make a wiremock optional, enabled when the 'testing' feature is enabled.
The goal is to reduce the number of dependencies, with the downside that
the test code coverage will drop.

Wiremock is currently used only on 'registrar_agent' tests to mock
responses from the registrar service.

Note: wiremock was moved to be an optional regular dependency because
optional dev-dependencies are not supported.
see: rust-lang/cargo#1596

Signed-off-by: Anderson Toshiyuki Sasaki <ansasaki@redhat.com>

Cargo.toml

@@ -43,16 +43,19 @@ tss-esapi = "7.1.0"
 thiserror = "1.0"
 uuid = {version = "0.8", features = ["v4"]}
 zmq = {version = "0.9.2", optional = true}
+# wiremock was moved to be a regular dependency because optional
+# dev-dependencies are not supported
+# see: https://github.com/rust-lang/cargo/issues/1596
+wiremock = {version = "0.5", optional = true}
 
 [dev-dependencies]
 actix-rt = "2"
-wiremock = "0.5"
 
 [features]
 # The features enabled by default
 default = ["with-zmq", "legacy-python-actions"]
 # this should change to dev-dependencies when we have integration testing
-testing = []
+testing = ["wiremock"]
 # Whether the agent should be compiled with support to listen for notification
 # messages on ZeroMQ
 with-zmq = ["zmq"]

src/registrar_agent.rs

@@ -149,6 +149,7 @@ pub(crate) async fn do_register_agent(
     }
 }
 
+#[cfg(feature = "testing")]
 #[cfg(test)]
 mod tests {
     use super::*;