hardhat 0.1.4

• Setting indicators = "none" in default_formula_blueprint() no longer
  accidentally expands character columns into dummy variable columns. They
  are now left completely untouched and pass through as characters. When
  indicators = "traditional" or indicators = "one_hot", character columns
  are treated as unordered factors (#139).

• The indicators argument of default_formula_blueprint() now takes character
  input rather than logical. To update:

  indicators = TRUE  -> indicators = "traditional"
  
  indicators = FALSE -> indicators = "none"
  

  Logical input for indicators will continue to work, with a warning, until
  hardhat 0.1.6, where it will be formally deprecated.

  There is also a new indicators = "one_hot" option which expands all factor
  columns into K dummy variable columns corresponding to the K levels of
  that factor, rather than the more traditional K - 1 expansion.