dtplyr 1.0.1

• Better handling for .data and .env pronouns (#138).

• dplyr verbs now work with NULL inputs (#129).

• joins do better job at determining output variables in the presence of
  duplicated outputs (#128). When joining based on different variables in x
  and y, joins consistently preserve column from x, not y (#137).

• lazy_dt() objects now have a useful glimpse() method (#132).

• group_by() now has an arrange parameter which, if set to FALSE, sets
  the data.table translation to use by rather than keyby (#85).

• rename() now works without data.table attached, as intended
  (@MichaelChirico, #123).