Test postgres-protocol

Author: sfackler

.travis.yml

@@ -12,3 +12,4 @@ script:
 - cargo test --manifest-path=postgres/Cargo.toml
 - cargo test --manifest-path=postgres/Cargo.toml --features "$(cargo read-manifest --manifest-path=postgres/Cargo.toml | jq -r '.features|keys|map(select(. != "with-security-framework" and . != "with-schannel"))|join(" ")')"
 - cargo test --manifest-path=tokio-postgres/Cargo.toml
+- cargo test --manifest-path=postgres-protocol/Cargo.toml