Add test cases so covr::package_coverage() exceeds 80% and devtools::test() returns no errors or warnings

Admin to change settings to make sure checks pass

• protect master branch
• require reviews
• add action to test package Since this is on github.com we won't be able to publish on the internal server directly.
• Change Github pages to use branch gh-pages

Opened by @javier-sanchez-alvarez-roche on old repo. Details: Roche/Global-HTA-Evidence-Open#4

• include a basic 3 state oncology model in the package to illustrate concepts and excel formula check

Make updates so rcmdcheck::rcmdcheck() does not show any errors or warnings

• add word list file
• check code is in quotes
• make sure check passes

Now weight_var is included in run_psm can link to use of https://github.com/Roche/MAIC for complete work flow

Priority updates

1. Inclusion of Gamma compatibility in STEM like outputs
2. Inclusion of Excel formula examples for STEM like outputs for transparency

restructure bootstrap code so checks on data are only performed once

• potentially as a separate function combining run_psm and boot_psm functionality into a single call

add a function similar to summary_psm which will return a tibble of:

• KM estimates of survival
• Hazard estimates (pwe)
• Hazard estimates (smoothed)
• Cumulative hazard
  That could then be used for diagnostic plots