bump jsonfield version up

requirements/base.txt

 # edX Internal Requirements
-edx-submissions>=2.0.6,<3.0.0
+edx-submissions>=2.0.7,<3.0.0
 git+https://github.com/edx/django-rest-framework.git@1ceda7c086fddffd1c440cc86856441bbf0bd9cb#egg=djangorestframework==3.6.3
 git+https://github.com/edx/XBlock.git@xblock-1.0.1#egg=XBlock==1.0.1
 git+https://github.com/edx/xblock-sdk.git@v0.1.4#egg=xblock-sdk==0.1.4
@@ -11,7 +11,7 @@ defusedxml>=0.4.1,<1.0.0
 django-model-utils>=2.3.1,<3.0.0
 django-nose>=1.4.1,<2.0.0
 dogapi>=1.2.1,<2.0.0
-jsonfield>=1.0.3,<2.0.0
+jsonfield>=2.0.2,<3.0.0
 lazy>=1.1,<2.0
 libsass>=0.10.0,<1.0.0
 loremipsum>=1.0.5,<2.0.0