Export conjugate distributions and interface functions
With this release, the following API functions are exported:
posterior
posterior_canon
posterior_rand
posterior_rand!
posterior_randmodel
posterior_mode
fit_map
The following conjugate prior distributions (not already defined in Distributions.jl) are also exported:
NormalInverseChisq
NormalGamma
NormalInverseGamma
NormalWishart
NormalInverseWishart