add ci

.travis.yml

+# Based on the "trust" template v0.1.2
+# https://github.com/japaric/trust/tree/v0.1.2
+
+dist: trusty
+language: rust
+services: docker
+sudo: required
+
+matrix:
+  include:
+    # Linux
+    - env: TARGET=x86_64-unknown-linux-gnu
+
+    # Bare metal
+    - env: TARGET=thumbv7em-none-eabi
+    - env: TARGET=thumbv7em-none-eabihf
+
+before_install:
+  - set -e
+  - rustup self update
+
+install:
+  - sh ci/install.sh
+  - source ~/.cargo/env || true
+
+script:
+  - bash ci/script.sh
+
+after_script: set +e
+
+cache:
+  cargo: true
+  directories:
+    - $HOME/.xargo
+
+before_cache:
+  # Travis can't cache files that are not readable by "others"
+  - chmod -R a+r $HOME/.cargo
+
+branches:
+  only:
+    - auto
+    - master
+    - try
+
+notifications:
+  email:
+    on_success: never

ci/install.sh

+set -ex
+
+main() {
+    # This fetches latest stable release of Xargo
+    local tag=$(git ls-remote --tags --refs --exit-code https://github.com/japaric/xargo \
+                       | cut -d/ -f3 \
+                       | grep -E '^v[0.1.0-9.]+$' \
+                       | sort --version-sort \
+                       | tail -n1)
+
+    curl -LSfs https://japaric.github.io/trust/install.sh | \
+        sh -s -- \
+           --force \
+           --git japaric/xargo \
+           --tag $tag \
+           --target x86_64-unknown-linux-musl
+}
+
+main

ci/script.sh

+# This script takes care of testing your crate
+
+set -ex
+
+main() {
+    xargo check --target $TARGET
+}
+
+# we don't run the "test phase" when doing deploys
+if [ -z $TRAVIS_TAG ]; then
+    main
+fi