Feature/preparation for wheel & Docker

[HYLcool]

• For wheel packaging:
  • To package a wheel package that satisfies the requirements of PyPi, we remove or replace those dependencies from URLs (kenlm and some models from spacy)
  • Add more invoking methods for tools/process_data.py and tools/analyze_data.py:
    • python -m data_juicer.tools.process_data and python -m data_juicer.tools.analyze_data for pip installation
    • dj-process and dj-analyze command line tools
• For Docker:
  • Add a Dockerfile for building the docker image of data-juicer
• Others:
  • Set the default value of count threshold to 0 in the main app.py for issue What causes visualization to be blank? #22
  • Add missing default arguments to configs/config_all.yaml from distributed processing
  • Replace images used in README with URLs.

[yxdyc]

LGTM