v2.3.0

Fixes

• Fix various issues resulting in errors for models fit using static HMC (thanks
  to Cole Monnahan).
• Deprecate burnin argument to as.shinystan. Use warmup instead. Only
  relevant for models not fit using Stan.

New features

• Add NUTS energy diagnostic plots to Diagnose page
• Allowing passing sampler_params to as.shinystan. This makes it possible to
  display sampler diagnositcs for HMC/NUTS even if not using Stan's implementation
  of those algorithms (thanks to Cole Monnahan).