Given the chunks coming from imagemagick are getting stored memory and
then tucked into a cache, this function could as easily return a buffer
via callback. Streaming is just making it more complex. (And trickier to
test!)
- The information stored in `makeImage`'s `options` parameter is better served
in its `data` parameter,
- Remove the (no longer used) `colorscheme` parameter to `makeTemplate`,
- We can already get to the contents of the URL query parameter `style` through
that `data` parameter in `getRequest`,
- Relocation of the code to set badge data related to the flat style into
`getBadgeData`,
- Code style (adding semicolons).
Related to issue #159.
