Install pytest-bdd (which will eventually replace behave)

- Copy over the current tests from behave into the new directory that
  pytest-bdd will use them in

Co-authored-by: Micah Jerome Ellison <micah.jerome.ellison@gmail.com>

tests/features/data/templates/sample.template

@@ -0,0 +1,19 @@
+---
+extension: txt
+---
+
+{% block journal %}
+{% for entry in entries %}
+{% include entry %}
+{% endfor %}
+
+{% endblock %}
+
+{% block entry %}
+{{ entry.title }}
+{{ "-" * len(entry.title) }}
+
+{{ entry.body }}
+
+{% endblock %}
+`