diff --git a/.travis.yml b/.travis.yml
index 9c94e4347..ed782b1ea 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,14 +1,13 @@
 # vim ft=yaml
-# travis-ci.org definition for python-patterns build
+dist: xenial
 language: python
 
 sudo: false
 
 python:
   - "2.7"
-  - "3.4"
-  - "3.5"
   - "3.6"
+  - "3.7"
 
 cache:
   - pip
diff --git a/requirements-dev.txt b/requirements-dev.txt
index f6cec75db..c33c1dbce 100644
--- a/requirements-dev.txt
+++ b/requirements-dev.txt
@@ -3,3 +3,4 @@ pytest~=4.1
 pytest-cov~=2.6
 flake8~=3.6
 codecov~=2.0
+mock~=2.0