Increase galaxy page size to reduce number of requests

[felixfontein]

Increate the requested version list page size to 100 (default is 10) to reduce number of queries made. (100 is the maximum size; see https://github.com/ansible/galaxy/blob/devel/galaxy/api/v2/pagination.py#L21)

[dmsimard]

Works for me!

I tested it and it doesn't fix all the HTTP 520 errors but it does save on the amount of calls.
Anecdotally:

• before: 1m 27s and ctrl+f 520 returns 382 hits (so probably 191 errors as they are printed twice)
• after: 0m 52s and ctrl+f 520 returns 256 hits (so probably 128 errors)

[felixfontein]

@dmsimard @abadger thanks for reviewing this!