make travis happy

Author: zookzook

.travis.yml

@@ -5,6 +5,10 @@ elixir:
   - 1.6
   - 1.7
   - 1.8
+  - 1.9
+
+otp_release:
+  - '19.1'
 
 install:
   - wget http://fastdl.mongodb.org/linux/mongodb-linux-x86_64-${MONGODB}.tgz
@@ -27,4 +31,4 @@ env:
     - MONGODB=3.2.20
     - MONGODB=3.4.16
     - MONGODB=3.6.6
-    - MONGODB=4.0.9
+    - MONGODB=4.2.0

mix.exs

@@ -7,7 +7,7 @@ defmodule Mongodb.Mixfile do
     [app: :mongodb_driver,
      version: @version,
      elixirc_paths: elixirc_paths(Mix.env),
-     elixir: "~> 1.5",
+     elixir: "~> 1.6",
      name: "mongodb-driver",
      deps: deps(),
      docs: docs(),