Build doc tests in build script

Close #192

scripts/build.sh

@@ -1,6 +1,14 @@
 #!/usr/bin/env bash
 set -e
 
+# Target triple of the host machine. Set to x86-64 Linux by default, as that's
+# the correct value for the CI server.
+#
+# Unfotunately there doesn't seem to be a way to tell Cargo to just use the
+# target of the host machine, and since we override the default target in
+# `.cargo/config` for convenience, this variable is required.
+HOST_TARGET=${HOST_TARGET:-x86_64-unknown-linux-gnu}
+
 # Fail build, if there are any warnings.
 export RUSTFLAGS="-D warnings"
 
@@ -10,6 +18,7 @@ if [ "$TRAVIS_RUST_VERSION" != beta ] && [ "$TRAVIS_RUST_VERSION" != nightly ];
 fi
 
 function build() {
+    cargo test --verbose --features=$1,no-target-warning --target=$HOST_TARGET
     cargo build --verbose --features=$1-rt,no-target-warning --examples
 }