fix to remove unneeded @import of all of reshape which was causing check warnings
Merge pull request #116 from gavinsimpson/fix-namespace-check-error

fix to remove unneeded @import of all of reshape which was causing check...
quote package names in library() statements
use library() instead of require() to load packages; quote package names to load
Merge pull request #118 from gavinsimpson/tests-require

Minor fixes to how packages are loaded in tests
Add testthat and knitr to suggests as per issue #115
Merge pull request #119 from gavinsimpson/add-pkg-suggests

Add testthat and knitr to suggests as per issue #115