In image.py, SECTION_CHAR should be better defined

[cj-wong]

photo-dash/photo_dash/image.py

Line 36 in 89bc82f

SECTION_CHAR = int(16 * 10 / 16)

Right now, the value uses hard-coded numbers to determine the pixel width of one monospace character, given a font and size.

Plus, the 16 * 10 / 16 looks very tacky...