Rect does not support floating point coordinates

Originally reported by: **Daniel Pope (Bitbucket: [lordmauve](https://bitbucket.org/lordmauve), GitHub: [lordmauve](https://github.com/lordmauve))**

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This is confusing:

>>> from pygame import Rect
>>> Rect(1.5, 2.6, 7, 0.1)

It is inconsistent with Python's own number types, because Python tries to minimise the distinction between integral and float types.

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- Bitbucket: https://bitbucket.org/lordmauve/pgzero/issue/12

Reproduce the documented Rect(1.5, 2.6, 7, 0.1) example and inspect the project’s Rect usage and related tests; the payload names no source file or test entry point. Done means the behavior for floating-point coordinates is consistent with the requested Python number handling and is covered by a regression test.

Written by the indexing model from the issue text.