update DESCRIPTION

[almartin82]

includes dependency on on triebeard package (installation fails without.)

[almartin82]

@DerekYves excited to find a wrapper for the google maps API! small change including a triebeard dependency. here's what I saw on install w/o triebeard installed:

> install_github("DerekYves/placement")
Downloading GitHub repo DerekYves/placement@master
from URL https://api.github.com/repos/DerekYves/placement/zipball/master
Installing placement
"C:/Users/amartin/DOCUME~1/R/R-32~1.5/bin/x64/R" --no-site-file  \
  --no-environ --no-save --no-restore --quiet CMD INSTALL  \
  "C:/Users/amartin/AppData/Local/Temp/RtmpkjhS4K/devtools27f45757af3/DerekYves-placement-224a0ef"  \
  --library="C:/Users/amartin/Documents/R/R-3.2.5/library" --install-tests 

* installing *source* package 'placement' ...
** R
** preparing package for lazy loading
Error in loadNamespace(j <- i[[1L]], c(lib.loc, .libPaths()), versionCheck = vI[[j]]) : 
  there is no package called 'triebeard'
ERROR: lazy loading failed for package 'placement'
* removing 'C:/Users/amartin/Documents/R/R-3.2.5/library/placement'
Error: Command failed (1)
> library(placement)
Error in library(placement) : there is no package called ‘placement’
> 
> install.packages('triebeard')
trying URL 'https://cran.rstudio.com/bin/windows/contrib/3.2/triebeard_0.3.0.zip'
Content type 'application/zip' length 623950 bytes (609 KB)
downloaded 609 KB

package ‘triebeard’ successfully unpacked and MD5 sums checked

The downloaded binary packages are in
    C:\Users\amartin\AppData\Local\Temp\RtmpkjhS4K\downloaded_packages
> 
> library(devtools)
> install_github("DerekYves/placement")
Downloading GitHub repo DerekYves/placement@master
from URL https://api.github.com/repos/DerekYves/placement/zipball/master
Installing placement
"C:/Users/amartin/DOCUME~1/R/R-32~1.5/bin/x64/R" --no-site-file  \
  --no-environ --no-save --no-restore --quiet CMD INSTALL  \
  "C:/Users/amartin/AppData/Local/Temp/RtmpkjhS4K/devtools27f41f0734a3/DerekYves-placement-224a0ef"  \
  --library="C:/Users/amartin/Documents/R/R-3.2.5/library" --install-tests 

* installing *source* package 'placement' ...
** R
** preparing package for lazy loading
** help
*** installing help indices
** building package indices
** testing if installed package can be loaded
*** arch - i386
*** arch - x64
* DONE (placement)
> library(placement)

[DerekYves]

Thanks! You're correct. I merged the change. must be a new dependency for one of the other dependencies. Thanks you. Derek