Add CircleCI configuration.

Also jsonschema has been updated because the configured version, 2.6.0,
conflicted with the version required by poetry.

Fixes: #3

Author: Auke Willem Oosterhoff

.circleci/config.yml

@@ -0,0 +1,10 @@
+version: 2.1
+jobs:
+  build:
+    docker:
+      - image: circleci/python:3.7.3
+    steps:
+      - checkout
+      - run:
+          name: run tests
+          command: make deps && make test

requirements.txt

@@ -1 +1 @@
-jsonschema==2.6.0
+jsonschema==3.0.1

requirements_dev.txt

@@ -5,5 +5,4 @@ coverage==4.5.2
 pytest-asyncio==0.10.0
 pytest-cov==2.6.1
 pytest==4.1.1
-twine==1.12.1
 freezegun==0.3.11

setup.py

@@ -20,7 +20,7 @@
     ],
     packages=find_packages(),  # Required
     install_requires=[
-        'jsonschema (==2.6.0)',
+        'jsonschema (==3.0.1)',
     ],
     dependency_links=[],  # Optional
     include_package_data=True,