Pushes up versions to python to 3.7 and celery to ~=4.3

{{cookiecutter.project_slug}}/backend/app/Pipfile

@@ -20,7 +20,7 @@ pyjwt = "*"
 python-multipart = "*"
 email-validator = "*"
 requests = "*"
-celery = "==4.2.1"
+celery = "~=4.3"
 passlib = {extras = ["bcrypt"],version = "*"}
 tenacity = "*"
 pydantic = "*"

{{cookiecutter.project_slug}}/backend/backend.dockerfile

@@ -1,6 +1,6 @@
-FROM tiangolo/uvicorn-gunicorn-fastapi:python3.6
+FROM tiangolo/uvicorn-gunicorn-fastapi:python3.7
 
-RUN pip install celery==4.2.1 passlib[bcrypt] tenacity requests emails "fastapi>=0.7.1" uvicorn gunicorn pyjwt python-multipart email_validator jinja2 psycopg2-binary alembic SQLAlchemy
+RUN pip install celery~=4.3 passlib[bcrypt] tenacity requests emails "fastapi>=0.7.1" uvicorn gunicorn pyjwt python-multipart email_validator jinja2 psycopg2-binary alembic SQLAlchemy
 
 # For development, Jupyter remote kernel, Hydrogen
 # Using inside the container:

{{cookiecutter.project_slug}}/backend/celeryworker.dockerfile

@@ -1,6 +1,6 @@
-FROM python:3.6
+FROM python:3.7
 
-RUN pip install raven celery==4.2.1 passlib[bcrypt] tenacity requests "fastapi>=0.7.1" emails pyjwt email_validator jinja2 psycopg2-binary alembic SQLAlchemy
+RUN pip install raven celery~=4.3 passlib[bcrypt] tenacity requests "fastapi>=0.7.1" emails pyjwt email_validator jinja2 psycopg2-binary alembic SQLAlchemy
 
 # For development, Jupyter remote kernel, Hydrogen
 # Using inside the container:

{{cookiecutter.project_slug}}/backend/tests.dockerfile

@@ -1,4 +1,4 @@
-FROM python:3.6
+FROM python:3.7
 
 RUN pip install requests pytest tenacity passlib[bcrypt] "fastapi>=0.7.1" psycopg2-binary SQLAlchemy