Add possibility to control extrapolation in ppc_km_overlay() and ppc_km_overlay_grouped()

[Sakuski]

Fixes #346

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 98.61%. Comparing base (e4df4b6) to head (a5d4829).

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #353   +/-   ##
=======================================
  Coverage   98.60%   98.61%           
=======================================
  Files          35       35           
  Lines        5539     5550   +11     
=======================================
+ Hits         5462     5473   +11     
  Misses         77       77           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[jgabry]

This is great, thank you! I made a change to print message if the user doesn't change the default value of 1.2. This is just to alert the user that the plot will look different than they're used to if they don't change it to Inf. Your documentation already made this clear, but since we're changing the default appearance of the plot I think it's good to print a message to the console too. I think eventually we can remove this message once this new default has been in the package for a while.

[jgabry]

I'll wait for the unit tests to run again but after that I think this is ready to merge. Thanks again.