Add jinja2 as requirement

requirements.txt

@@ -4,3 +4,4 @@ flask
 pytest
 pytest-mock
 responses
+jinja2
\ No newline at end of file

setup.py

@@ -11,7 +11,8 @@ setup(
     install_requires=[
         'requests',
         'jsonschema',
-        'flask'
+        'flask',
+        'jinja2'
     ],
     include_package_data=True,
 )