Description of proposed changes

• .circleci/config.yml updates:

  • use $BASH_ENV to set and share environment variable (PATH) among multiple run steps
  • rename to workflow/job to "unit-n-workflow-tests"

• save_gmt: fix the typo in the module import (save_gmt.py geo_velocity.h5 #900)

• cli/load_data: check -t smallbaselineApp.cfg existence and print out error msg (ISCE2 StripmapStack load_data looking for ionUnwFile #891 (comment))

• tsview: show the reference index/date info on the slider as title

Reminders

• Fix save_gmt.py geo_velocity.h5 #900, ISCE2 StripmapStack load_data looking for ionUnwFile #891
• Pass Codacy code review (green)
• Pass Pre-commit check (green)
• Pass Circle CI test (green)
• Make sure that your code follows our style. Use the other functions/files as a basis.
• If modifying functionality, describe changes to function behavior and arguments in a comment below the function declaration.