Add docker

.travis.yml

@@ -1,17 +1,19 @@
 language: node_js
 node_js:
 - 8.11.1
-addons:
-  apt:
-    sources:
-    - ubuntu-toolchain-r-test
-    packages:
-    - g++-4.8
-  sauce_connect:
-    username:
-      secure: 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
-    access_key:
-      secure: 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
+# addons:
+#   apt:
+#     sources:
+#     - ubuntu-toolchain-r-test
+#     packages:
+#     - g++-4.8
+#   sauce_connect:
+#     username:
+#       secure: 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
+#     access_key:
+#       secure: 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
+services:
+  - docker
 cache:
   apt: true
   directories: