added versioning headers to the API

src/paperless/settings.py

@@ -115,6 +115,8 @@ REST_FRAMEWORK = {
     ],
     'DEFAULT_VERSIONING_CLASS': 'rest_framework.versioning.AcceptHeaderVersioning',
     'DEFAULT_VERSION': '1',
+    # Make sure these are ordered and that the most recent version appears
+    # last
     'ALLOWED_VERSIONS': ['1', '2']
 }
 
@@ -131,6 +133,7 @@ MIDDLEWARE = [
     'django.middleware.locale.LocaleMiddleware',
     'django.middleware.common.CommonMiddleware',
     'django.middleware.csrf.CsrfViewMiddleware',
+    'paperless.middleware.ApiVersionMiddleware',
     'django.contrib.auth.middleware.AuthenticationMiddleware',
     'django.contrib.messages.middleware.MessageMiddleware',
     'django.middleware.clickjacking.XFrameOptionsMiddleware',