Added a cargo clean before the first cargo build (to ensure only one copy of irc

for doc tests).

.travis.yml

@@ -4,6 +4,7 @@ sudo: false
 script:
   - chmod +x mktestconfig.sh
   - ./mktestconfig.sh
+  - cargo clean
   - cargo build --verbose
   - rustdoc --test README.md -L target/debug/deps
   - cargo test --verbose --features "toml yaml"