Minor updates to setup scripts

As I'm familiarizing myself with the setup scripts currently in the PyARC repo, there are a few changes I had to make to get set up on VTR, namely:

1. scripts/setup_conda.sh needs to be called by prepending source to it, otherwise the conda environment does not actually persist after the script finishes. There is now an error to check that this is the case
2. Updating gitignore to add more files / directories that are added as a result of running the setup scripts
3. There is no bash command "no", "yes n" should be used instead
4. The default cmake version on VTR is really old and a newer version is needed to run scripts/setup_dependencies.sh, I am adding this as a package to install in scripts/setup_openmc.sh