Update cargo-web update

Author: pitdicker

.travis.yml

@@ -53,7 +53,8 @@ matrix:
         #- cargo --list | egrep "\binstall-update$" -q || cargo install cargo-update
         #- cargo install-update -i cargo-web
         # Cargo has errors with sub-commands so ignore updating for now:
-        - cargo --list | egrep "^\s*web$" -q || cargo install cargo-web
+        #- cargo --list | egrep "^\s*web$" -q || cargo install cargo-web
+        - cargo install --force cargo-web
       script:
         - cargo web test --target wasm32-unknown-unknown --nodejs --features=stdweb