i2extras 0.2.1

• {i2extras} now explicitly 'Depends' on the upstream
  {incidence2} package and
  enforces a minimum version requirement upon this (i.e. incidence2 >= 2.0.0).

• fit_curve() and the corresponding plotting method, plot.incidence2_fit()
  have been adapted to account for the new structure and plotting methods of
  <incidence2> objects.

• find_peak() is now a wrapper around the keep_peaks() function from
  the underlying incidence2 package.

• add_rolling_average() is no longer a generic function and will now error if
  not called on an <incidence2> object. It now returns the original input with
  additional rolling average columns but does not change the underlying objects
  class. Internally the code has been refactored to make use of
  data.table::frollmean() and function arguments updated accordingly. Due to
  the changes to add_rolling_average(), the plot method for
  <incidence2_rolling> objects has been removed.

• estimate_peak() can now (optionally) return multiple peaks.

• fit_model() is now defunct and will error if called.