Dev dependency patch

[mhpob]

Should fix #186.

• Imports dplyr instead of plyr in DESCRIPTION
• Removes GISTools from DESCRIPTION/Imports at the expense of a north arrow and scale bar in figure 1 of detection_range_handout
• Removes undeclared dependency on reshape2 from detection_range_handout
• Small adjustments to detection_range_handout to allow the document to knit (incl. adjustments introduced by breaking change to crw_in_polygon)
• Newly-knitted PDF and HTML versions of detection_range_handout

[mhpob]

Tests fail R CMD check since it can't find testthat -- added testthat to DESCRIPTION in hopes of fixing this.