Linter Cppcheck.

[bdevierno1]

Bug Report

Current Behavior
Current installation script for cppcheck is failing after update to ubuntu 20.

Environment

• OS: Ubuntu 20

Possible Solution

Update the yaml file to specify ubuntu 20 instead of latest
Update installation script for correct installation of cppcheck.

Output for cppcheck may differ depending on the version. Ensure the current python linter parsing script returns expected output.

[menglander2019]

I can take care of this once I get ubuntu-20 or a cloudlab account

[twood02]

I suggest we make two changes for this.

First, instead of using runs-on: ubuntu-latest, we should force it to use ubuntu-20.04. This won't actually fix the current issue (since ubuntu-latest == ubuntu-20.04 which is causing the whole problem), but it will ensure that we have a consistent environment and doesn't automatically change just because GitHub adds support for a newer version of Ubuntu.

Second, we need to fix the cppcheck instatllation. Right now we use sudo apt-get install cppcheck=1.82-1 to install a particular version. This is giving an error because that version isn't supported by Ubuntu 20.04. It looks like we should be able to use 2.1-1 based on this page.

[twood02]

resolved by #306