I'm trying to set up a Docker image based on Ubuntu 18.04 that runs some code with Python 3.7

The dockerfile specifically mentions installing python 3.7 but in the image binary folder there is also python 3.6 that the image uses as default and which I don't even need.

What change would I need to make in order to only have python 3.7 on the image?

The dockerfile currently looks like this:

```
FROM ubuntu:18.04

#format changes required for asammdf v3.4.0
ENV LANG C.UTF-8
ENV LC_ALL C.UTF-8

#install python 3.7 and pip
RUN apt-get update && apt-get install -y \
    python3.7 \
    python3-pip

#set main entry point as working directory
WORKDIR /

RUN pip3 install --upgrade setuptools

RUN alias python3=/usr/bin/python3.7
RUN pip3 install -r requirements.txt

```

Later details:

Added the `alias` command hoping that it would work but it seems to be ignored in the dockerfile, the execution still goes to python3.6

The requirements installation works fine but installs all packages in the 3.6 directory so even if I manually use the python3.7 execution while in the container, it doesn't see the installed modules