set_width bottom aligns cells in latex

[eweisbrod]

huxtable("some text") %>%
set_width(1) %>%
print_latex()

the set_width command adds parbox[b] to the latex code, which bottom aligns the cell contents even though the valign of the cell contents says top. If I manually change the [b] to [t] in the outputted latex code then the cell contents top-align properly and everything works.

[hughjonesd]

This reduces to #9. Thanks for the report.