Fix error of lib RPostgres not being installed

[fabio1079]

A biblioteca RPostgres não estava sendo instalada corretamente:

Execution halted
ERROR: lazy loading failed for package ‘RPostgres’
* removing ‘/usr/local/lib/R/site-library/RPostgres’

The downloaded source packages are in
	‘/tmp/RtmpUoP8bv/downloaded_packages’
Warning messages:
1: In install.packages(c("RPostgres"), repos = "http://cran.rstudio.com/") :
  installation of package ‘hms’ had non-zero exit status
2: In install.packages(c("RPostgres"), repos = "http://cran.rstudio.com/") :
  installation of package ‘RPostgres’ had non-zero exit status

Esse PR corrige a instalação dessa lib.

[ArthurJahn]

@fabio1079 Você chegou a testar a instalação fora do ambiente do AirFlow?

[andersonms1]

RUN R -e "install.packages(c('https://cran.r-project.org/src/contrib/Archive/RPostgres/RPostgres_1.3.3.tar.gz'), repos=NULL, type='"SOURCE"')"

Uma maneira de instalar passando a versão. @ArthurJahn @fabio1079