add rust and cargo, upgrade pip

[critzo]

Added these packages and upgrade pip command to resolve a build issue with Balena. poetry==1.1.7 build failed since the cryptography package couldn't be built under PEP 517. See error log below. This now builds on Balena, and we'll cross check travis.

[main]           =============================DEBUG ASSISTANCE=============================
[main]       error: [Errno 2] No such file or directory: 'cargo': 'cargo'
[main]       ----------------------------------------
[main]     
[main]       ERROR: Failed building wheel for cryptography
[main]     
[main]     Failed to build cryptography
[main]     ERROR: Could not build wheels for cryptography which use PEP 517 and cannot be installed directly
[main]     
[main]     WARNING: You are using pip version 21.0.1; however, version 21.2.4 is available.
[main]     You should consider upgrading via the '/usr/local/bin/python3.7 -m pip install --upgrade pip' command.
[main]     
[main]     Removing intermediate container 1759c33ca36b
[main]     The command '/bin/sh -c pip install 'poetry==1.1.7'' returned a non-zero code: 1

---

This change is