Bump to 0.4.2 (rstudio#147)

* Bump to 0.4.2.

* Note Apache 2 changes.

* Update domain.

* Skip failing test on CRAN.

* Print fails on cran for some odd reason.

* Escape high-ASCII

* Don't test high ASCII on cran.

Don't wildcard allow-origin by default. (rstudio#144)

* Don't wildcard allow-origin by default.

This could be considered a vulnerability in how Plumber behaved previously. This, by default, allows cross-origin GET, HEAD, and POST requests using the standard headers from any origin. We've decided that this is something you should opt-in to, so we're removing this as the default.

* Support OPTIONS requests

Makes it feasible for you to build your own CORS handler.

* Note NEWS changes.

Brace for rstudio#101.

Skip pandoc-dependent tests where not available.

Added utils imports.

Added NEWS.

Added logo