Adjust test to round colors between 0 and 255 to 255 to account for systems that use subpixel anti-aliasing for text on canvas.
Merge pull request #846 from AnalyticalGraphicsInc/fixWriteTextToCanvasSpec

Adjust test to round colors between 0 and 255 to 255 to account for systems that use subpixel anti-aliasing for text on canvas.