Add Travis CI

.travis.yml

@@ -0,0 +1,26 @@
+language: python
+
+matrix:
+  include:
+    - python: 3.6
+      env: TOXENV=py36-test
+    - python: 3.7
+      env: TOXENV=py37-test
+    - python: 3.7
+      env: TOXENV=lint
+    - python: 3.7
+      env: TOXENV=sort
+    - python: 3.7
+      env: TOXENV=format
+    - python: 3.7
+      env: TOXENV=type
+    - python: 3.7
+      env: TOXENV=docs
+    - python: 3.7
+      env: TOXENV=metadata-release
+
+install:
+  - pip install tox==3.13.2
+
+script:
+  - tox -v

README.rst

@@ -12,6 +12,10 @@ flat-tree
    :target: https://badge.fury.io/py/flat_tree
    :alt: PyPI Package
 
+.. image:: https://travis-ci.com/datpy/flat-tree.svg?branch=master
+   :target: https://travis-ci.com/datpy/flat-tree
+   :alt: Travis CI result
+
 .. image:: https://readthedocs.org/projects/flat-tree/badge/?version=latest
    :target: https://flat-tree.readthedocs.io/en/latest/?badge=latest
    :alt: Documentation Status