Improve validate solutions script & fix pre-commit error (#3253)

* Trying to time every solution

* Proposal 2 for timing PE solutions:

- Use pytest fixture along with --capture=no flag to print out the
  top DURATIONS slowest solution at the end of the test sessions.
- Remove the print part and try ... except ... block from the test
  function.

* Proposal 3 for timing PE solutions:

Completely changed the way I was performing the tests. Instead of
parametrizing the problem numbers and expected output, I will
parametrize the solution file path.

Steps:
- Collect all the solution file paths
- Convert the paths into a Python module
- Call solution on the module
- Assert the answer with the expected results

For assertion, it was needed to convert the JSON list object to
Python dictionary object which required changing the JSON file itself.

* Add type hints for variables

* Fix whitespace in single_qubit_measure

Author: dhruvmanila

Diff for: .travis.yml

@@ -16,10 +16,8 @@ jobs:
       script:
         - pytest --doctest-modules --durations=10 --cov-report=term-missing:skip-covered --cov=project_euler/ project_euler/
     - name: Project Euler Solution
-      install:
-        - pip install pytest-subtests
       script:
-        - pytest --tb=short project_euler/validate_solutions.py
+        - pytest --tb=short --durations=10 project_euler/validate_solutions.py
 after_success:
   - scripts/build_directory_md.py 2>&1 | tee DIRECTORY.md
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