Updated typo (regster to register)

[sinramyeon]

There was a cute typo

• Please check if the PR fulfills these requirements

• The commit message follows our guidelines. See Contributing guide

• Tests for the changes have been added (for bug fixes / features)

• Docs have been added / updated (for bug fixes / features)

• What kind of change does this PR introduce? (Bug fix, feature, docs update, ...)

• What is the current behavior? (You can also link to an open issue here)

• What is the new behavior (if this is a feature change)?

• Does this PR introduce a breaking change? (What changes might users need to make in their application due to this PR?)

• Other information:

---

This change is 

[CLAassistant]

All committers have signed the CLA.

[codecov[bot]]

Codecov Report

Merging #60 into master will not change coverage. The diff coverage is n/a.

@@           Coverage Diff           @@
##           master      #60   +/-   ##
=======================================
  Coverage   47.74%   47.74%           
=======================================
  Files          22       22           
  Lines        1240     1240           
=======================================
  Hits          592      592           
  Misses        616      616           
  Partials       32       32

---

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 215750b...a1c89bc. Read the comment docs.

[Dexus]

Thank you @hero0926 .