added easingStyle 'none' to disable scroll-animation

[makrohard]

as mentioned in #104

[codecov-io]

Codecov Report

❗ No coverage uploaded for pull request base (master@c169480). Click here to learn what that means.
The diff coverage is 66.66%.

@@            Coverage Diff            @@
##             master     #109   +/-   ##
=========================================
  Coverage          ?   98.51%           
=========================================
  Files             ?       23           
  Lines             ?      202           
  Branches          ?       47           
=========================================
  Hits              ?      199           
  Misses            ?        3           
  Partials          ?        0           

Impacted Files	Coverage Δ
src/scrollnav.js	100.00% <ø> (ø)
src/scrollTo.js	90.90% <66.66%> (ø)

---

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 c169480...b5ff8e8. Read the comment docs.