remove unnecessary dependencies and imports
diff --git a/DESCRIPTION b/DESCRIPTION
index 740667d..6fe178c 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -16,10 +16,13 @@
 Description: Posterdown expands on RMarkdown to generate
     PDF and HTML conference posters.
 License: MIT + file LICENSE
-Encoding: UTF-8
-LazyData: true
 URL: https://github.com/brentthorne/posterdown
 BugReports: https://github.com/brentthorne/posterdown/issues
-Imports: bookdown, ggplot2, pagedown, kableExtra, Cairo, rmarkdown, knitr, yaml, ggspatial
-SystemRequirements: GNU make, Pandoc (>= 2.2.3)
+Imports: 
+    knitr,
+    pagedown,
+    rmarkdown,
+    yaml
+Encoding: UTF-8
+LazyData: true
 RoxygenNote: 6.1.1
diff --git a/NAMESPACE b/NAMESPACE
index 2f7ae9c..4391252 100644
--- a/NAMESPACE
+++ b/NAMESPACE
@@ -5,8 +5,3 @@
 export(posterdown_html)
 export(posterdown_latex)
 export(posterdown_pdf)
-import(bookdown)
-import(ggplot2)
-import(knitr)
-import(pagedown)
-import(rmarkdown)
diff --git a/R/posterdown.R b/R/posterdown.R
index c23ea6c..de6fd42 100644
--- a/R/posterdown.R
+++ b/R/posterdown.R
@@ -11,9 +11,4 @@
 #'
 #' @docType package
 #' @name posterdown
-#' @import rmarkdown
-#' @import bookdown
-#' @import pagedown
-#' @import ggplot2
-#' @import knitr
 NULL