```r
tweets_julia <- read_csv("data/juliasilge_tweets.csv")
tweets_dave <- read_csv("data/drob_tweets.csv")
tweets <- bind_rows(tweets_julia %>% 
                      mutate(person = "Julia"),
                    tweets_dave %>% 
                      mutate(person = "David")) %>%
  mutate(created_at = ymd_hms(created_at))
```