Add colorette to the benchmarks

[prantlf]

Attempts to fix #35. I upgraded chalk to the latest (minor) version too.

Both kleur and colorette are the fastest with colorette having the upper hand. It appears that kleur trades run-time for loading-time performance :-)

The numbers:

$ node load

chalk: 11.326ms
kleur: 0.662ms
kleur/colors: 0.438ms
ansi-colors: 1.961ms
colorette: 2.13ms

$ node colors

# All Colors
  ansi-colors      x 218,607 ops/sec ±0.35% (91 runs sampled)
  chalk            x 918,282 ops/sec ±0.26% (96 runs sampled)
  colorette        x 1,529,758 ops/sec ±0.87% (96 runs sampled)
  kleur            x 1,166,639 ops/sec ±0.64% (92 runs sampled)
  kleur/colors     x 1,426,030 ops/sec ±0.23% (93 runs sampled)

# Stacked colors
  ansi-colors      x 26,428 ops/sec ±0.95% (94 runs sampled)
  chalk            x 589,847 ops/sec ±0.15% (94 runs sampled)
  colorette        x 115,505 ops/sec ±0.81% (93 runs sampled)
  kleur            x 89,383 ops/sec ±1.10% (93 runs sampled)
  kleur/colors     x 111,107 ops/sec ±0.10% (97 runs sampled)

# Nested colors
  ansi-colors      x 78,378 ops/sec ±0.08% (93 runs sampled)
  chalk            x 127,300 ops/sec ±0.21% (97 runs sampled)
  colorette        x 160,043 ops/sec ±0.22% (98 runs sampled)
  kleur            x 135,730 ops/sec ±1.11% (94 runs sampled)
  kleur/colors     x 144,491 ops/sec ±0.40% (97 runs sampled)

[codecov-io]

Codecov Report

Merging #44 (a2cd1e5) into master (fc9cc25) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master      #44   +/-   ##
=======================================
  Coverage   98.77%   98.77%           
=======================================
  Files           2        2           
  Lines         163      163           
  Branches       28       28           
=======================================
  Hits          161      161           
  Misses          1        1           
  Partials        1        1           

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update fc9cc25...a2cd1e5. Read the comment docs.