Add coverage and codecov integration

.coveragerc

@@ -0,0 +1,13 @@
+[run]
+branch = True
+source = floweaver
+
+[report]
+exclude_lines =
+    if self.debug:
+    pragma: no cover
+    raise NotImplementedError
+    if __name__ == .__main__.:
+ignore_errors = True
+omit =
+    test/*

.travis.yml

@@ -7,7 +7,8 @@ matrix:
     - python: 3.6
     - python: 3.5
 install:
-  - pip install pytest matplotlib
-  - pip install .
+  - pip install '.[test]'
 script:
-  - py.test
+  - pytest --cov=./
+after_success:
+  - codecov

setup.py

@@ -67,7 +67,7 @@ def find_version(*file_paths):
     ],
     extras_require={
         'dev': [],
-        'test': ['pytest', 'matplotlib'],
+        'test': ['pytest', 'matplotlib', 'codecov', 'pytest-cov'],
         'docs': ['sphinx', 'nbsphinx', 'jupyter_client', 'ipykernel', 'ipysankeywidget']
     },
 )