Merge pull request #8 from yoni/master

Bug fixes.
Fixes bug in renviron file handling
Merge pull request #9 from rtcurtis/master

Fixes bug in renviron file handling
Testing and bug fix.

* Re-introduce integration tests.
* Fix a bug with the creation of custom `.Rbundle` library.
* Bump version up to 0.3.0.
* .Rbuildignore ignores IntelliJ droppings and README.