[Tests] run subpackage tests at top level.

.travis.yml

@@ -0,0 +1,18 @@
+language: node_js
+node_js:
+  - "5"
+  - "4"
+  - "iojs"
+env:
+  - 'TEST_DIR=packages/eslint-config-airbnb'
+before_install:
+  - 'cd $TEST_DIR'
+  - 'if [ "${TRAVIS_NODE_VERSION}" != "0.9" ]; then case "$(npm --version)" in 1.*) npm install -g npm@1.4.28 ;; 2.*) npm install -g npm@2 ;; esac ; fi'
+  - 'if [ "${TRAVIS_NODE_VERSION}" != "0.6" ] && [ "${TRAVIS_NODE_VERSION}" != "0.9" ]; then npm install -g npm; fi'
+script:
+  - 'npm test'
+sudo: false
+matrix:
+  fast_finish: true
+  allow_failures:
+    - node_js: "iojs"