Increment version number to 0.4.1

Bump version to 0.4.0, final changes for release (#23)

Remove function skipping some tests for old R versions that are no lo…

…nger supported

Prepare 0.3.1 for CRAN

Prepare for CRAN

* Bump version
* Add revdepcheck

Update for CRAN resubmission

* Remove "in R" from Description and Title fields
* Add examples to functions that were missing them
* Fix home country bug in ph_example