install.packages("dplyr", repos='http://cran.us.r-project.org')
install.packages("maps", repos='http://cran.us.r-project.org')
install.packages("leaflet", repos='http://cran.us.r-project.org')
install.packages("stringr", repos='http://cran.us.r-project.org')
install.packages("rtweet", repos='http://cran.us.r-project.org')