Revert "Add clippy job"

This reverts commit 8ae689863d.

.travis.yml

@@ -36,14 +36,6 @@ matrix:
           script:
             - cargo build --all --all-features -j 1  || exit 1
             - cargo test  --all --all-features -j 1  || exit 1
-        - language: rust
-          rust: nightly
-          allow_failure: true
-          cache:
-            cargo: true
-          script:
-            - cargo install clippy || exit 1
-            - cargo-clippy || exit 1
 
 
 addons: