fix(ci): ensure all examples compile with the specified feature-set

Due to cargo's feature unification, a full build of our workspace doesn't actually check whether the examples compile as standalone projects.

We add a new CI check that iterates through all crates in the `examples/` directory and runs a plain `cargo check` on them. Any failure is bubbled up via `set -e`, thus failing CI in case one of the `cargo check` commands fails.

To fix the current failures, we construct a simple TCP transport everywhere where we were previously using `development_transport`. That is because `development_transport` requires `mplex` which is now deprecated.

Related #3657.
Related #3809.

Pull-Request: #3811.

examples/rendezvous/src/bin/rzv-discover.rs

@@ -43,7 +43,7 @@ async fn main() {
 
     let mut swarm = SwarmBuilder::with_tokio_executor(
         tcp::tokio::Transport::default()
-            .upgrade(Version::V1)
+            .upgrade(Version::V1Lazy)
             .authenticate(noise::NoiseAuthenticated::xx(&key_pair).unwrap())
             .multiplex(yamux::YamuxConfig::default())
             .boxed(),

examples/rendezvous/src/bin/rzv-identify.rs

@@ -39,7 +39,7 @@ async fn main() {
 
     let mut swarm = SwarmBuilder::with_tokio_executor(
         tcp::tokio::Transport::default()
-            .upgrade(Version::V1)
+            .upgrade(Version::V1Lazy)
             .authenticate(noise::NoiseAuthenticated::xx(&key_pair).unwrap())
             .multiplex(yamux::YamuxConfig::default())
             .boxed(),

examples/rendezvous/src/bin/rzv-register.rs

@@ -39,7 +39,7 @@ async fn main() {
 
     let mut swarm = SwarmBuilder::with_tokio_executor(
         tcp::tokio::Transport::default()
-            .upgrade(Version::V1)
+            .upgrade(Version::V1Lazy)
             .authenticate(noise::NoiseAuthenticated::xx(&key_pair).unwrap())
             .multiplex(yamux::YamuxConfig::default())
             .boxed(),

examples/rendezvous/src/main.rs

@@ -53,7 +53,7 @@ async fn main() {
 
     let mut swarm = SwarmBuilder::with_tokio_executor(
         tcp::tokio::Transport::default()
-            .upgrade(Version::V1)
+            .upgrade(Version::V1Lazy)
             .authenticate(noise::NoiseAuthenticated::xx(&key_pair).unwrap())
             .multiplex(yamux::YamuxConfig::default())
             .boxed(),