Nodupe unit tests (#697)

* Added many more NoDupe tests

* Add final tests to nodupe

* Add nodupe sub-class tests

* Add test docs on using VSCode

tests/README.md

@@ -43,6 +43,31 @@ Code coverage can be generated by adding `--cov-config=tests/.coveragerc --cov=s
 
 Junit-compatible unit test report can be had with by adding `--junitxml=tests/junit/test-results.xml` to the command-line.
 
+### Visual Studio Code
+
+If you want to run this in VSCode, and have it do all the things nicely, you'll need the following extensions:
+- [Python](https://marketplace.visualstudio.com/items?itemName=ms-python.python)  
+  Provides all the smarts for Python development (IntelliSense, linting, debugging, code formatting, refactoring, unit tests, etc..)  
+- [Coverage Gutters](https://marketplace.visualstudio.com/items?itemName=ryanluker.vscode-coverage-gutters)  
+  Provides a way to track code coverage in VSCode
+- [Python Environment Manager](https://marketplace.visualstudio.com/items?itemName=donjayamanne.python-environment-manager)  
+  Not strictly required, but really handy if you're working on a number of Python projects
+- [GitLens — Git supercharged](https://marketplace.visualstudio.com/items?itemName=eamodio.gitlens)  
+  Not strictly required, but *very* strongly recommended as it makes VS Code's git features fully functional
+
+Beyond that, changing a few options in your settings file will make it all work; thusly:
+```json
+{
+    "python.testing.pytestArgs": [
+        "tests", "-v", 
+        "--cov-config=tests/.coveragerc", "--cov=sarracenia", "--cov-report=xml", "--cov-report=html",
+        "--failed-dependency-action=run", "--missing-dependency-action=run"
+    ],
+    "python.testing.unittestEnabled": false,
+    "python.testing.pytestEnabled": true,
+    "coverage-gutters.coverageBaseDir": "tests/coverage",
+}
+```
 
 ## Docker
 You can also run the exact same tests from within a Docker container if you want to avoid having to (re)-provision clean installs.