Refactor testing harness to use defaults (#808)

* Refactor testing harness to use defaults

- Move tests into defaultly named test folders
- Use default test suffix of ".test" instead of "_test"
- Make cluster-store tests unit tests by adding more
    nesting, so that order of tests doesn't matter

Signed-off-by: Sebastian Malton <sebastian@malton.name>

Co-authored-by: Sebastian Malton <smalton@mirantis.com>

package.json

@@ -60,7 +60,6 @@
     ]
   },
   "jest": {
-    "testRegex": ".*_(spec|test)\\.[jt]sx?$",
     "collectCoverage": false,
     "verbose": true,
     "testEnvironment": "node",