update test environment requirements

.isort.cfg

@@ -5,6 +5,7 @@ known_third_party =
     antlr4,
     dateutil,
     medallion,
+    pyjarowinkler,
     pytest,
     pytz,
     requests,

.travis.yml

@@ -1,16 +1,13 @@
 sudo: false
 language: python
 cache: pip
+dist: xenial
 python:
   - "2.7"
   - "3.4"
   - "3.5"
   - "3.6"
-matrix:
-  include:
-    - python: 3.7 # https://github.com/travis-ci/travis-ci/issues/9069#issuecomment-425720905
-      dist: xenial
-      sudo: true
+  - "3.7"
 install:
   - pip install -U pip setuptools
   - pip install tox-travis pre-commit

tox.ini

@@ -9,6 +9,7 @@ deps =
   pytest-cov
   coverage
   taxii2-client
+  pyjarowinkler
   medallion
 commands =
   pytest --ignore=stix2/test/v20/test_workbench.py --ignore=stix2/test/v21/test_workbench.py --cov=stix2 stix2/test/ --cov-report term-missing