installing ropensci/magick behind a firewall - r

Question

I'm attempting to use the gganiminate library and I'm having an issue when I call gganimate::gganimate(myplot). The issue appears to be with a dependency library, magick.
When I call the function I get the following warning:
gganimate::gganimate(p)
1: running command 'C:\WINDOWS\system32\cmd.exe /c convert --version' had status 4
2: In find_magic() : ImageMagick not installed yet!
In im.convert(img.files, output = path.expand(movie.name), ... :
Please install ImageMagick first or put its bin path into the system PATH variable
So I try to install magick separately. I'm on a machine at a client so installing packages from github requires me to provide info to get through the firewall. I've installed other libraries from github with this machine using the same technique successfully. However, magick appears to be bumping into other problems. Below is my code and the error:
devtools::install_github("ropensci/magick",httr::set_config(httr::use_proxy("xx.xxx.xx.xx",xxxx)))
Downloading GitHub repo ropensci/magick#master
from URL https://api.github.com/repos/ropensci/magick/zipball/master
Installing magick
"C:/PROGRA~1/R/R-34~1.3/bin/x64/R" \
--no-site-file --no-environ --no-save \
--no-restore --quiet CMD INSTALL \
"C:/Users/r631265/AppData/Local/Temp/1/RtmpS0efnQ/devtools18fc5f2414b/ropensci-magick-7925af3" \
--library="C:/Users/r631265/Documents/R/win-library/3.4" \
--install-tests
* installing *source* package 'magick' ...
** libs
*** arch - i386
rm -f RcppExports.o animation.o attributes.o base.o color.o composite.o config.o convolve.o device.o edit.o fonts.o options.o resize.o transformations.o magick.dll
Linking to imagemagagick-6.9.9
"C:/PROGRA~1/R/R-34~1.3/bin/i386/Rscript.exe" "../tools/winlibs.R" 6.9.9
Error in curl::curl_download(sprintf("https://github.com/rwinlib/imagemagick%s/archive/v%s.zip", :
schannel: failed to receive handshake, SSL/TLS connection failed
Calls: <Anonymous> -> .Call
Execution halted
make: *** [winlibs] Error 1
Warning: running command 'make -f "Makevars.win" -f "C:/PROGRA~1/R/R-34~1.3/etc/i386/Makeconf" -f "C:/PROGRA~1/R/R-34~1.3/share/make/winshlib.mk" CXX='$(CXX11) $(CXX11STD)' CXXFLAGS='$(CXX11FLAGS)' CXXPICFLAGS='$(CXX11PICFLAGS)' SHLIB_LDFLAGS='$(SHLIB_CXX11LDFLAGS)' SHLIB_LD='$(SHLIB_CXX11LD)' SHLIB="magick.dll" OBJECTS="RcppExports.o animation.o attributes.o base.o color.o composite.o config.o convolve.o device.o edit.o fonts.o options.o resize.o transformations.o"' had status 2
ERROR: compilation failed for package 'magick'
* removing 'C:/Users/r631265/Documents/R/win-library/3.4/magick'
In R CMD INSTALL
Installation failed: Command failed (1)
I think perhaps my firewall details aren't getting passed into: curl::curl_download(sprintf("https://github.com/rwinlib/imagemagick%s/archive/v%s.zip",...)
Network security is a bit of a black box to me so I'm not sure what else to try or if I'm diagnosing the issue correctly. Any help would be greatly appreciated!