update Dockerfile

Signed-off-by: Nischay Ram Mamidi <NischayPro@gmail.com>

Dockerfile

@@ -12,7 +12,10 @@ WORKDIR /app
 COPY requirements /app/requirements
 
 # py dev tooling
-RUN python3 -m pip install --no-cache-dir  --upgrade pip && python3 --version && pip3 install --no-cache-dir --upgrade setuptools && pip3 install --no-cache-dir -r requirements/app.txt -r requirements/dev.txt -r requirements/test.txt
+RUN python3 -m pip install --no-cache-dir --upgrade pip && python3 --version && \
+    pip3 install --no-cache-dir --upgrade setuptools && \
+    PYV=$(python3 -c "import sys;t='{v[0]}.{v[1]}'.format(v=list(sys.version_info[:2]));sys.stdout.write(t)") && \
+    pip3 install --no-cache-dir -r requirements/$PYV/app.txt -r requirements/$PYV/dev.txt -r requirements/$PYV/test.txt
 
 # Copy code and meta/config data
 COPY setup.* .flaskenv wsgi.py /app/