0.4.0

This is a long overdue release of pykelihood with many breaking changes that have accumulated over time.

Breaking changes

• Renamed stats_utils module to profiler
• Data must now be provided to kernels on creation, unbound kernels are
  no longer allowed
• Parameters are no longer subclasses of float, use .value to get
  their stored value
• ConditioningMethods were removed, their uses can be replaced with
  score functions
• The biv parameter to the Profiler was removed, confidence
  intervals are univariate only

Removed

Many distributions and utilities which were created with a specific use
case in mind and aren't generally useful have been removed:

• MixtureExponentialModel,
• ExtendedGPD,
• PointProcess,
• CompositionDistribution,
• DetrendedFluctuationAnalysis,
• pettitt_test,
• threshold_selection_GoF and threshold_selection_gpd_NorthorpColeman,
• extreme values visualisation routines,
• process samplers (Poisson and Hawkes).

New features

• Metrics: {pp,qq}_l{1,2}_distance, likelihood, expo_ratio
• Log-normal distribution
• Plotting functions now accept an ax argument to use instead of the
  global plt figure
• Constant kernel (most useful for testing)
• Kernels have a with_covariate method that returns a new kernel
  with the provided data as covariate, but all parameters are kept the
  same
• The random_state parameter to the Distribution.rvs method is now
  explicit and no longer hidden in the **kwargs

Bug fixes

• Fixed fit_instance for nested kernels with fixed values
• Fixed the TruncatedDistribution which forgot its bounds after fitting
• A parameter which shows up in several places in a distribution will
  keep the same value when fitting instead of returning independent
  parameters

Other

• Add section to README on fitting other score functions than the likelihood
• Add changelog with all version changes up to this one