correct template and fix no-pagination

[priyanshunayan]

Fixes #485

Checklist

• My branch is up-to-date with upstream/develop branch.
• Everything works and tested for Python 3.5.2 and above.

Description

• This PR removes the error thrown on making GET request on Collection endpoints when started via cli with --no-pagination flag.
• As we have discussed earlier, the wrong template was returned. So one minor change this PR does is that replaces parentheses by curly braces and add ? symbol to indicate key-value pairs are accepted. Ref: https://tools.ietf.org/id/draft-gregorio-uritemplate-08.html#rfc.section.3.2.8

Change logs

• Curly braces instead of paranthesis
• Maximum possible number of members in non-paginated collection