text: Title: `predict_proba` documented with wrong output shape
  Body: According the docs, `predict_proba` returns
  > numpy array of shape (n_samples,)
  
  However it actually returns `(n_samples, n_classes)`
  
  https://github.com/yzhao062/pyod/blob/c8d07f723c588aee40fccad6d0258c814384a057/pyod/models/base.py#L197-L203