Increase coverage (#20)

* Increasing more coverage of seeder

* Adding error cases and unknown strategy test

Signed-off-by: paulholiday <paul.holiday@ralawise.com>

* Adding error cases

Signed-off-by: paulholiday <paul.holiday@ralawise.com>

* Added further error cases

Signed-off-by: paulholiday <paul.holiday@ralawise.com>

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Signed-off-by: paulholiday <paul.holiday@ralawise.com>
Co-authored-by: paulholiday <paul.holiday@ralawise.com>