Add Cairo as required package
In reference to issue #5
diff --git a/.Rproj.user/441ADA46/persistent-state b/.Rproj.user/441ADA46/persistent-state
index 52b0d9d..431a782 100644
--- a/.Rproj.user/441ADA46/persistent-state
+++ b/.Rproj.user/441ADA46/persistent-state
@@ -1,8 +1,8 @@
build-last-errors="[]"
build-last-errors-base-dir="~/Documents/GitHub/posterdown/"
-build-last-outputs="[{\"output\":\"==> R CMD INSTALL --preclean --no-multiarch --with-keep.source posterdown\\n\\n\",\"type\":0},{\"output\":\"* installing to library ‘/home/thornux/R/x86_64-pc-linux-gnu-library/3.5’\\n\",\"type\":1},{\"output\":\"\",\"type\":1},{\"output\":\"* installing *source* package ‘posterdown’ ...\\n\",\"type\":1},{\"output\":\"** R\\n\",\"type\":1},{\"output\":\"** inst\\n\",\"type\":1},{\"output\":\"** byte-compile and prepare package for lazy loading\\n\",\"type\":1},{\"output\":\"\",\"type\":1},{\"output\":\"** help\\n\",\"type\":1},{\"output\":\"*** installing help indices\\n\",\"type\":1},{\"output\":\"\",\"type\":1},{\"output\":\"** building package indices\\n\",\"type\":1},{\"output\":\"** testing if installed package can be loaded\\n\",\"type\":1},{\"output\":\"\",\"type\":1},{\"output\":\"* DONE (posterdown)\\n\",\"type\":1},{\"output\":\"\",\"type\":1}]"
+build-last-outputs="[{\"output\":\"==> R CMD INSTALL --preclean --no-multiarch --with-keep.source posterdown\\n\\n\",\"type\":0},{\"output\":\"* installing to library ‘/home/thornux/R/x86_64-pc-linux-gnu-library/3.5’\\n\",\"type\":1},{\"output\":\"* installing *source* package ‘posterdown’ ...\\n\",\"type\":1},{\"output\":\"** R\\n\",\"type\":1},{\"output\":\"** inst\\n\",\"type\":1},{\"output\":\"** byte-compile and prepare package for lazy loading\\n\",\"type\":1},{\"output\":\"\",\"type\":1},{\"output\":\"** help\\n\",\"type\":1},{\"output\":\"*** installing help indices\\n\",\"type\":1},{\"output\":\"** building package indices\\n\",\"type\":1},{\"output\":\"** testing if installed package can be loaded\\n\",\"type\":1},{\"output\":\"\",\"type\":1},{\"output\":\"* DONE (posterdown)\\n\",\"type\":1},{\"output\":\"\",\"type\":1}]"
compile_pdf_state="{\"errors\":[],\"output\":\"\",\"running\":false,\"tab_visible\":false,\"target_file\":\"\"}"
files.monitored-path=""
find-in-files-state="{\"handle\":\"\",\"input\":\"\",\"path\":\"\",\"regex\":true,\"results\":{\"file\":[],\"line\":[],\"lineValue\":[],\"matchOff\":[],\"matchOn\":[]},\"running\":false}"
-imageDirtyState="0"
-saveActionState="0"
+imageDirtyState="1"
+saveActionState="-1"