fontawesome() Hyphen Inclusion Reference Issue

[YUSUF-KHAN1]

Session info -----------------------------------------------------------------------------------------------------
setting value
version R version 3.4.3 (2017-11-30)
system x86_64, mingw32
ui RStudio (1.1.453)
language (EN)
collate English_United States.1252
tz America/New_York
date 2018-09-24

This code runs successfully:

windows()
fa <- fontawesome(rep('fa-github',20))
d <- data.frame(x=rnorm(20),
y=rnorm(20),
label=fa)

ggplot(d, aes(x, y, color=label, label=label)) +
geom_text(family='fontawesome-webfont', size=6)+
xlab(NULL)+ylab(NULL) +
theme(legend.text=element_text(family='fontawesome-webfont'))
#######################################################################
When the argument passed to the fontawesome function includes a hyphen then it does not run. The error occurs with the fontawesome function:

fa <- fontawesome(rep('fa-jedi-order',20))
Invalid: fa-jedi-order, fa-jedi-order,[...]

Only thing changed from first set of code was 'fa-github' >> 'fa-jedi-order'
I've tried variations of removing the second hyphen for an underscore, space, period.

Thanks