testing: docker tests now work on travis

All of the platforms tested currently fail in some way currently, but
the infrastructure itself appears to be working.  As we have moved to
the legacy infrastructure (required in order to use docker), the tests
do run slower now.  To compensate for that, i686 builds are only done on
stable and we do not test every version between the current stable and
the oldest version we support.

Signed-off-by: Paul Osborne <osbpau@gmail.com>

.travis.yml

@@ -1,35 +1,35 @@
----
+language: rust
 sudo: required
+dist: trusty
 services:
   - docker
-language: rust
+
 rust:
   - 1.1.0  # Oldest supported version
-  - 1.2.0
-  - 1.3.0
-  - 1.4.0
-  - 1.5.0
-  - 1.6.0
-  - 1.7.0
   - stable
   - beta
   - nightly
 
 script:
-  - sh ci/run-travis.sh
+  - bash ci/run-travis.sh
+
+env:
+  - ARCH=x86_64
 
 os:
   - linux
   - osx
 
-env:
-  - ARCH=x86_64
-  - ARCH=i686
-
 # Failures on nightly shouldn't fail the overall build.
 matrix:
   fast_finish: true
   include:
+    - os: linux
+      env: ARCH=i686
+      rust: stable
+    - os: osx
+      env: ARCH=i686
+      rust: stable
     - os: linux
       env: TARGET=aarch64-unknown-linux-gnu DOCKER_IMAGE=posborne/rust-cross:arm
       rust: 1.7.0

ci/run-travis.sh

@@ -27,8 +27,15 @@ if [ "$TARGET" = "" ]; then
   TARGET=$HOST
 fi
 
+if [ "$TARGET" = "i686-unknown-linux-gnu" ]; then
+    sudo apt-get -y update
+    sudo apt-get install -y gcc-multilib
+fi
+
 if [ "$DOCKER_IMAGE" = "" ]; then
-  RUST_TEST_THREADS=1 cargo test
+  export RUST_TEST_THREADS=1
+  curl -sSL "https://raw.githubusercontent.com/carllerche/travis-rust-matrix/master/test" | bash
+  cargo doc --no-deps
 else
   export RUST_VERSION=${TRAVIS_RUST_VERSION}
   export RUST_TARGET=${TARGET}