Example Scripts: Migration to Python3

[JBorrow]

Hi possible contributors!

Something that would make for a great first issue is to download and compile SWIFT, and then check out the examples and try running a few. The majority of these examples currently use python2 scripts for initial conditions generation and analysis; it would be great if you could upgrade these to use python3 instead.

Thanks!

[pwdraper]

@JBorrow I believe this is done? If so please close the issue.