R version 3.4 is not correct link

[muschellij2]

Similar to #86, but for Windows/Appveyor, the link for R 3.4 is now incorrect for binary:
https://ci.appveyor.com/project/neuroconductor-devel-releases/afnir/build/1.0.1/job/a9wh5x2aayiugh26#L20

which references r: 3.4: https://github.com/neuroconductor-devel-releases/afnir/commit/a7cedf2626904339928b51625b9881bbe6790d3e#diff-180360612c6b8c4ed830919bbb4dd459R37

http://cran.rstudio.com/bin/windows/base/old/3.4/R-3.4-win.exe
Must either be:
http://cran.rstudio.com/bin/windows/base/old/3.4.0/, to point to http://cran.rstudio.com/bin/windows/base/old/3.4.0/R-3.4.0-win.exe or 3.4.4: http://cran.rstudio.com/bin/windows/base/old/3.4.4/R-3.4.4-win.exe