Clinica 0.3.8

Added

• Add option to run deeplearning-prepare-data in output of t1-extension pipeline and
  also custom pipelines (PR #150).
• Add Build and publish documentation with CI (PR #146).
• Add CHANGELOG.md file

Changed

• Harmonize PET tracers handling (ML/DL/Stats) (PR #137).
• Behaviour of ADNI converter: some minor bugs and updated wrt ADNI3. E.g., the
  field age_bl was added. (PR #139, #138, #140, #142)

Fixed

• Add DataDictionary_NIFD_.xlsx file when using NIFD2BIDS.