oppia: Unable to run backend tests

I used this command to run a backend test

python -m scripts.run_backend_tests --test_target=scripts.linters.general_purpose_linter_test

ERROR LOG

Error 1
Traceback (most recent call last):
  File "/home/nishantwrp/Desktop/dev/open-source/oppia/core/tests/gae_suite.py", line 113, in <module>
    main()
  File "/home/nishantwrp/Desktop/dev/open-source/oppia/core/tests/gae_suite.py", line 100, in main
    suites = create_test_suites(test_target=parsed_args.test_target)
  File "/home/nishantwrp/Desktop/dev/open-source/oppia/core/tests/gae_suite.py", line 83, in create_test_suites
    if test_target else [loader.discover(
  File "/usr/lib/python2.7/unittest/loader.py", line 100, in loadTestsFromName
    parent, obj = obj, getattr(obj, part)
AttributeError: 'module' object has no attribute 'general_purpose_linter_test'

11:23:08 ERROR scripts.linters.general_purpose_linter_test: 9.6 secs
Error 1
Traceback (most recent call last):
  File "/home/nishantwrp/Desktop/dev/open-source/oppia/core/tests/gae_suite.py", line 113, in <module>
    main()
  File "/home/nishantwrp/Desktop/dev/open-source/oppia/core/tests/gae_suite.py", line 100, in main
    suites = create_test_suites(test_target=parsed_args.test_target)
  File "/home/nishantwrp/Desktop/dev/open-source/oppia/core/tests/gae_suite.py", line 83, in create_test_suites
    if test_target else [loader.discover(
  File "/usr/lib/python2.7/unittest/loader.py", line 100, in loadTestsFromName
    parent, obj = obj, getattr(obj, part)
AttributeError: 'module' object has no attribute 'general_purpose_linter_test'


+------------------+
| SUMMARY OF TESTS |
+------------------+

= create_test_suites(test_target=parsed_args.test_target)
  File "/home/nishantwrp/Desktop/dev/open

------------------------------------------------------
    WARNING: FAILED TO RUN scripts.linters.general_purpose_linter_test

    This is most likely due to an import error.
------------------------------------------------------

Traceback (most recent call last):
  File "/usr/lib/python2.7/runpy.py", line 174, in _run_module_as_main
    "__main__", fname, loader, pkg_name)
  File "/usr/lib/python2.7/runpy.py", line 72, in _run_code
    exec code in run_globals
  File "/home/nishantwrp/Desktop/dev/open-source/oppia/scripts/run_backend_tests.py", line 441, in <module>
    main()
  File "/home/nishantwrp/Desktop/dev/open-source/oppia/scripts/run_backend_tests.py", line 402, in main
    raise Exception('WARNING: No tests were run.')
Exception: WARNING: No tests were run.

@srijanreddy98 was also facing this issue.