Pin wabt to a working revision (#440)

library/stdarch/.travis.yml

@@ -28,7 +28,7 @@ matrix:
     - env: TARGET=wasm32-unknown-unknown
       before_script:
         - git clone --recursive https://github.com/WebAssembly/wabt
-        - (cd wabt && make -j4)
+        - (cd wabt && git reset --hard a0bdeb7 && make -j4)
         - export PATH=$PATH:$PWD/wabt/bin
       script:
         - cargo build --target wasm32-unknown-unknown -p stdsimd
@@ -55,7 +55,6 @@ matrix:
         cargo clippy --all -- -D clippy-pedantic
   allow_failures:
     - env: CLIPPY=On TARGET=x86_64-unknown-linux-gnu NO_ADD=1
-    - env: TARGET=wasm32-unknown-unknown
 
 before_install:
   # FIXME (travis-ci/travis-ci#8920) shouldn't be necessary...