update dependencies

requirements.txt

-Django==3.1.5
-django-bootstrap4==2.3.1
+Django==3.1.8
+django-bootstrap4==3.0.1
 django-fontawesome-5==1.0.18
 django-split-settings==1.0.1
 django-timezone-field==4.1.2
-djangorestframework==3.12.2
-django-simple-history==2.12.0
+djangorestframework==3.12.4
+django-simple-history==3.0.0
 django-registration-redux==2.9
-django-debug-toolbar==3.2
+django-debug-toolbar==3.2.1
 django-bootstrap-datepicker-plus==3.0.5
 mysqlclient==2.0.3  # for production deployment
 pytz==2021.1