Description of proposed changes

• rename bulk_plate_motion to plate_motion: including changes in:

  • mintpy.plate_motion.py
  • mintpy.cli.plate_motion.py
  • mintpy.__main__
  • setup.py

• utils.readfile.read(): add no_data_values arg to be able to convert the no-data-value from one number to another number.

• utils.network: del the obsolete igram_perp_baseline_list() function

• use the Python context manager with statement to better control the file handle/lock (Resource temporarily unavailable #855).

Reminders

• Pass Codacy code review (green)
• Pass Circle CI test (green)
• If modifying functionality, describe changes to function behavior and arguments in a comment below the function declaration.