0.3.8 (2018-05-22)

• Add initial support for dataframe functionality.
• Add IO module for Owl's specific file operations.
• Add more helper functions in Array module in Base.
• Add core functions such as one_hot, slide, and etc.
• Fix normalisation neuron in neural network module.
• Fix building, installation, and publishing on OPAM.
• Fix broadcasting issue in Algodiff module.
• Support negative axises in some ndarray functions.
• Add more statistical distribution functions.
• Add another higher level wrapper for CBLAS module.