Change from pip + virtualenv to pipenv

Dockerfile

@@ -1,19 +1,10 @@
-FROM python:3.7-alpine as base
+FROM python:3.7-alpine
 
-FROM base as builder
-
-RUN mkdir /install
-WORKDIR /install
-
-COPY req.txt /requirements.txt
-
-RUN pip install --install-option="--prefix=/install" -r /requirements.txt
-
-FROM base
-
-COPY --from=builder /install /usr/local
 
 COPY . /app
+WORKDIR /app
+
+RUN pip install pipenv && pipenv install --system
 
 RUN date +%d-%m-%Y > /app/date