The `required` tag raises validation failure error when a boolean field
is defined as `false`:
```
ERROR "unable to parse tool file at "mongodb_tools.yaml": unable to parse tool "insert-one-device" as kind "mongodb-insert-one": [2:12] Key: 'Config.Canonical' Error:Field validation for 'Canonical' failed on the 'required' tag\n 1 | authRequired: []\n> 2 | canonical: false\n ^\n 3 | collection: Device\n 4 | database: xiar\n 5 | description: Inserts a single new document into the Device collection. The 'data' parameter must be a string containing the JSON object to insert.\n 6 | "
```
All the `required` tags are removed from the boolean `canonical` field
of the MongoDB tools. Unit tests are added.
