fix(UserSession): switch "duration" to "expiration" in IOAuth2Options

[gavinr]

AFFECTS PACKAGES:
@esri/arcgis-rest-auth

BREAKING CHANGE:
IOAuth2Options: "duration" is removed. Please use "expiration"

ISSUES CLOSED: #843

@tomwayson is there a better way to deprecate?

[codecov]

Codecov Report

Merging #845 (8d007aa) into master (3f43679) will not change coverage.
The diff coverage is 100.00%.

@@            Coverage Diff            @@
##            master      #845   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files          133       133           
  Lines         2352      2352           
  Branches       415       415           
=========================================
  Hits          2352      2352           

Impacted Files	Coverage Δ
packages/arcgis-rest-auth/src/UserSession.ts	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 3f43679...8d007aa. Read the comment docs.

[tomwayson]

thanks @gavinr, but I think we should either hold this until the next release, or change it to deprecate duration instead of remove it.

[tomwayson]

I was thinking we'd have both until the next breaking change so we would not have to do a breaking change for this release. We'd leave duration, but change the comments to indicate that it is deprecated and to use expiration instead. Then in the code below we'd use expiration || duration until the next major release.

[gavinr]

got it. That's what I initlally was doing, using the @deprecated tag, but then the build was erroring, saying it should not be used. I think I was probably just not doing it correctly. I'll bring that code back into this PR then re-ping you. Thanks!