rbind_pages doesn't handle named lists with data.frame columns.

[jasonelaw]

rbind_pages seems to have an issue with named lists that have data.frame columns:

df1 <- data.frame(f = letters[1:4], x = rnorm(4))
df2 <- data.frame(id = 1:4)
df2$value <- df1

jsonlite::rbind_pages(list(df2, df2))

jsonlite::rbind_pages(list(a = df2, b = df2))

Notice the value column is NA in the second call. I have opened a pull request that fixes the issue.