travis: test parity-util-mem on android

.travis.yml

@@ -8,12 +8,16 @@ matrix:
       rust: stable
       before_script:
         - rustup component add rustfmt
-    - os: linux
-      rust: beta
     - os: linux
       rust: nightly
       script:
-        - cargo check --all --benches
+        - cargo check --workspace --benches
+    - os: linux
+      rust: stable
+      install:
+        - cargo install cross
+      script:
+        - cross test --target=aarch64-linux-android -p parity-util-mem
     - os: osx
       osx_image: xcode11.3
       addons:
@@ -32,12 +36,10 @@ matrix:
 install:
   - curl https://rustwasm.github.io/wasm-pack/installer/init.sh -sSf | sh
 script:
-  - if [ "$TRAVIS_RUST_VERSION" == "stable" ] && [ "$TRAVIS_OS_NAME" == "linux" ]; then
+  - if [ "$TRAVIS_OS_NAME" == "linux" ]; then
     cargo fmt -- --check;
     fi
-  - cargo check --all --tests
-  - cargo check --all --benches
-  - cargo build --all
+  - cargo check --workspace --tests --benches
   - cargo test --all --exclude uint --exclude fixed-hash --exclude parity-crypto
   - if [ "$TRAVIS_RUST_VERSION" == "nightly" ]; then
     cd contract-address/ && cargo test --features=external_doc && cd ..;