Compile with -Xfatal-warnings on Scala 2.13

[fthomas]

No description provided.

[codecov]

Codecov Report

Merging #821 into master will not change coverage.
The diff coverage is 77.77%.

@@           Coverage Diff           @@
##           master     #821   +/-   ##
=======================================
  Coverage   92.96%   92.96%           
=======================================
  Files          62       62           
  Lines         768      768           
  Branches       12       12           
=======================================
  Hits          714      714           
  Misses         54       54           

Impacted Files	Coverage Δ
...ala/eu/timepit/refined/scalacheck/collection.scala	100.00% <ø> (ø)
...c/main/scala/eu/timepit/refined/cats/package.scala	91.11% <71.42%> (ø)
.../scala/eu/timepit/refined/api/RefinedTypeOps.scala	100.00% <100.00%> (ø)
...it/refined/internal/ApplyRefPartiallyApplied.scala	100.00% <100.00%> (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 1b8d5d2...bad98e5. Read the comment docs.