Fix poetry

Based on fastapi#460 (comment)

Author: yeger00

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

@@ -3,10 +3,9 @@ FROM tiangolo/uvicorn-gunicorn-fastapi:python3.7
 WORKDIR /app/
 
 # Install Poetry
-RUN curl -sSL https://raw.githubusercontent.com/python-poetry/poetry/master/get-poetry.py | POETRY_HOME=/opt/poetry python && \
-    cd /usr/local/bin && \
-    ln -s /opt/poetry/bin/poetry && \
-    poetry config virtualenvs.create false
+RUN curl -sSL https://install.python-poetry.org | POETRY_HOME=/opt/poetry python3
+ENV PATH="/opt/poetry/bin:$PATH"
+RUN poetry config virtualenvs.create false
 
 # Copy poetry.lock* in case it doesn't exist in the repo
 COPY ./app/pyproject.toml ./app/poetry.lock* /app/

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

@@ -3,10 +3,9 @@ FROM python:3.7
 WORKDIR /app/
 
 # Install Poetry
-RUN curl -sSL https://raw.githubusercontent.com/python-poetry/poetry/master/get-poetry.py | POETRY_HOME=/opt/poetry python && \
-    cd /usr/local/bin && \
-    ln -s /opt/poetry/bin/poetry && \
-    poetry config virtualenvs.create false
+RUN curl -sSL https://install.python-poetry.org | POETRY_HOME=/opt/poetry python3
+ENV PATH="/opt/poetry/bin:$PATH"
+RUN poetry config virtualenvs.create false
 
 # Copy poetry.lock* in case it doesn't exist in the repo
 COPY ./app/pyproject.toml ./app/poetry.lock* /app/