Update the minimum required version of DRF to 3.7.7

Closes #44, #45.

README.rst

@@ -11,8 +11,8 @@ Generate **real** Swagger/OpenAPI 2.0 specifications from a Django Rest Framewor
 
 Compatible with
 
-- **Django Rest Framework**: 3.7
-- **Django**: 1.11, 2.0
+- **Django Rest Framework**: 3.7.7
+- **Django**: 1.11.x, 2.0.x
 - **Python**: 2.7, 3.4, 3.5, 3.6
 
 Resources:

requirements/base.txt

@@ -7,6 +7,6 @@ future>=0.16.0
 six>=1.11.0
 uritemplate>=3.0.0
 
-djangorestframework>=3.7.0
+djangorestframework>=3.7.7
 Django>=1.11.7,<2.0; python_version <= "2.7"
 Django>=1.11.7; python_version >= "3.4"

tox.ini

@@ -15,7 +15,7 @@ deps =
     django111: Django>=1.11,<2.0
     django20: Django>=2.0,<2.1
 
-    drf37: djangorestframework>=3.7.3,<3.8
+    drf37: djangorestframework>=3.7.7,<3.8
 
     # test with the latest build of Django and django-rest-framework to get early warning of compatibility issues
     drfmaster: https://github.com/encode/django-rest-framework/archive/master.tar.gz