check for panicing code in ci

.travis.yml

@@ -7,6 +7,9 @@ matrix:
   allow_failures:
     - rust: nightly
   fast_finish: true
+install:
+  - cargo install --git https://github.com/Technolution/rustig rustig
 script:
-  - cargo build --verbose --all
-  - cargo test --verbose --all
+  - cargo build
+  - cargo test
+  - cargo build --release && ~/.cargo/bin/rustig -b target/release/parse_demo