Error(s) in re-building vignettes:
  ...
--- re-building ‘DependencySorting.Rmd’ using rmarkdown
Warning in engine$weave(file, quiet = quiet, encoding = enc) :
  Pandoc (>= 1.12.3) and/or pandoc-citeproc not available. Falling back to R Markdown v1.
Quitting from lines 118-121 (DependencySorting.Rmd) 
Error: processing vignette 'DependencySorting.Rmd' failed with diagnostics:
there is no package called 'webshot'
--- failed re-building ‘DependencySorting.Rmd’

--- re-building ‘ParametricExample.Rmd’ using rmarkdown
Warning in engine$weave(file, quiet = quiet, encoding = enc) :
  Pandoc (>= 1.12.3) and/or pandoc-citeproc not available. Falling back to R Markdown v1.
--- finished re-building ‘ParametricExample.Rmd’

--- re-building ‘coalesce.Rmd’ using rmarkdown
Warning in engine$weave(file, quiet = quiet, encoding = enc) :
  Pandoc (>= 1.12.3) and/or pandoc-citeproc not available. Falling back to R Markdown v1.
--- finished re-building ‘coalesce.Rmd’

--- re-building ‘joinController.Rmd’ using rmarkdown
Warning in engine$weave(file, quiet = quiet, encoding = enc) :
  Pandoc (>= 1.12.3) and/or pandoc-citeproc not available. Falling back to R Markdown v1.
Quitting from lines 200-203 (joinController.Rmd) 
Error: processing vignette 'joinController.Rmd' failed with diagnostics:
there is no package called 'webshot'
--- failed re-building ‘joinController.Rmd’

--- re-building ‘letExample.Rmd’ using rmarkdown
Warning in engine$weave(file, quiet = quiet, encoding = enc) :
  Pandoc (>= 1.12.3) and/or pandoc-citeproc not available. Falling back to R Markdown v1.

Attaching package: 'dplyr'

The following objects are masked from 'package:stats':

    filter, lag

The following objects are masked from 'package:base':

    intersect, setdiff, setequal, union

Loading required package: wrapr

Attaching package: 'wrapr'

The following object is masked from 'package:dplyr':

    coalesce

--- finished re-building ‘letExample.Rmd’

--- re-building ‘replyr.Rmd’ using rmarkdown
Warning in engine$weave(file, quiet = quiet, encoding = enc) :
  Pandoc (>= 1.12.3) and/or pandoc-citeproc not available. Falling back to R Markdown v1.

Attaching package: 'dplyr'

The following objects are masked from 'package:stats':

    filter, lag

The following objects are masked from 'package:base':

    intersect, setdiff, setequal, union

--- finished re-building ‘replyr.Rmd’

--- re-building ‘summary.Rmd’ using rmarkdown
Warning in engine$weave(file, quiet = quiet, encoding = enc) :
  Pandoc (>= 1.12.3) and/or pandoc-citeproc not available. Falling back to R Markdown v1.
--- finished re-building ‘summary.Rmd’

SUMMARY: processing the following files failed:
  ‘DependencySorting.Rmd’ ‘joinController.Rmd’

Error: Vignette re-building failed.
Execution halted