Update 'celery' and dependencies for Python 3.7+ support

Python 3.7 is supported from 'celery' version 4.3 upwards,
previous versions were hit by the following bug:
https://github.com/celery/celery/issues/4500

Similar commit in db: librespacefoundation/satnogs/satnogs-db@dc06369f

Signed-off-by: Fabian P. Schmidt <kerel@mailbox.org>

requirements-dev.txt

@@ -7,7 +7,7 @@
 apipkg==1.5
 atomicwrites==1.3.0
 attrs==19.3.0
-coverage==5.0
+coverage==5.0.1
 execnet==1.7.1
 factory-boy==2.11.1
 Faker==0.8.18
@@ -19,9 +19,9 @@ packaging==19.2
 pbr==5.4.4
 pluggy==0.13.1
 pur==5.2.2
-py==1.8.0
-pyparsing==2.4.5
-pytest==4.6.7
+py==1.8.1
+pyparsing==2.4.6
+pytest==4.6.8
 pytest-cov==2.6.1
 pytest-django==3.4.8
 pytest-forked==0.2
@@ -29,6 +29,6 @@ pytest-xdist==1.25.0
 python-dateutil==2.8.1
 text-unidecode==1.2
 toml==0.10.0
-tox==3.14.2
+tox==3.14.3
 virtualenv==16.7.9
-wcwidth==0.1.7
+wcwidth==0.1.8

requirements.txt

@@ -6,8 +6,8 @@
 amqp==2.5.2
 args==0.1.0
 backports.csv==1.0.7
-billiard==3.5.0.5
-celery==4.1.1
+billiard==3.6.1.0
+celery==4.3.0
 certifi==2019.11.28
 chardet==3.0.4
 Click==7.0

setup.cfg

@@ -29,7 +29,7 @@ install_requires =
     Django~=1.11.0
     django-shortuuidfield~=0.1.0
     django-jsonfield~=1.0.0
-    celery~=4.1.0
+    celery~=4.3.0
     internetarchive~=1.7.0
     # Deployment
     mysqlclient~=1.3.0