Speed up some draw bounds tests

[charlesej]

This update addresses the comment/issue mentioned by @MightyJosip in issue #1212 that the test_arc__bounding_rect() test is performing a lot of iterations and taking much longer than the other draw test cases. Changes were also made to some of the other draw bounds tests (ellipse/polygon/rect) to reduce their test times.

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Overview of changes:

• Reduced the size of the surfaces being checked
• Reduced the number of iterations on some of the test parameters

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Test details:

• ran three passes to average out times
• baseline
  • python: 3.8.1 (64bit)
    • cmd: python -Wd -m pygame.tests draw_test
      • Ran 205 tests in 57.065s
      • Ran 205 tests in 50.898s
      • Ran 205 tests in 50.937s
• with changes to bounding tests
  • python: 3.8.1 (64bit)
    • cmd: python -Wd -m pygame.tests draw_test
      • Ran 205 tests in 5.777s
      • Ran 205 tests in 5.869s
      • Ran 205 tests in 5.565s
  • python: 2.7.10 (64bit)
    • cmd: python -Wd -m pygame.tests draw_test
      • Ran 205 tests in 8.432s
      • Ran 205 tests in 6.878s
      • Ran 205 tests in 7.097s

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System details:

• os: windows 10 (64bit)
• python: 3.8.1 (64bit) and 2.7.10 (64bit)
• pygame: 2.0.0.dev7 (SDL: 2.0.10) at 2ff089b

[MightyJosip]

Thanks, in my opinion it looks great

[illume]

Now that's a speedup!