accessibility v1.1.0

New features

• The package now includes functions to estimate accessibility inequalities
  (palma_ratio() and gini_index()) and poverty (fgt_poverty()).
• New accessibility functions spatial_availability() and balancing_cost().
• New vignette "Calculating accessibility inequality and poverty".
• cost_to_closest() parameter n now accepts a numeric vector, instead of
  being restricted to a single number.
• cumulative_cutoff() parameters cutoff and travel_cost now accepts a
  numeric and a character vector, respectively, instead of being restricted to
  a single number/string.
• cumulative_interval() parameter interval now accepts a list of numeric
  vectors, instead of being restricted to a single vector.
• The decay functions can now take numeric vectors as input, instead of being
  restricted to a single number (in the case of decay_stepped(), both steps
  and weights can take a list of numeric vectors as input, instead of
  being restricted to a single numeric vector each).

Notes

• Various documentation tweaks.
• Added the new accessibility functions to the intro vignette.