PSAgraphics 2.1.3

• Minor update to fix CRAN notes.

PSAgraphics 2.1.2

• Maintainer has been updated.
• Source code is not on Github and uses the devetools and roxygen2 packages to manage package building.
• Minor updates to remove CRAN notes.
• Setup pacages properly in the imports list.
• Added a NEWS.md file to track changes to the package.