refactor: fix tutorial deployment issues

See merge request teraflow-h2020/controller!168

refactor: fix tutorial deployment issues

See merge request teraflow-h2020/controller!162

Merge branch 'feat/microk8s-deployment' of https://gitlab.com/teraflow-h2020/controller into pr-tutorial

feat(automation): implement ztpUpdate()

See merge request teraflow-h2020/controller!164

Signed-off-by: gkatsikas <gkatsikas@ubitech.eu>

feat(automation): implement ztpDelete()

See merge request teraflow-h2020/controller!165

Fix Device after changes in Monitoring component

See merge request teraflow-h2020/controller!166

Fix unitary tests to align with changes in monitoring component information model.

Fix monitoring loops to align with changes in monitoring component information model.

Modifications in the monitoring information model and skeleton of the methods...

See merge request teraflow-h2020/controller!163

Update 1-1-1-create-vm-oracle-virtualbox.md to clarify Ubuntu Server should be use instead of Desktop

refactor(policy): add validation at PolicyRuleDevice

See merge request teraflow-h2020/controller!161

refactor(policy): add validation at PolicyRuleService

See merge request teraflow-h2020/controller!160

refactor(policy): add validation at PolicyRuleCondition

See merge request teraflow-h2020/controller!159

- fixed parsing of custom rules in unitary tests

- Added missing log dump in unitary test

Common and Context changes:

See merge request teraflow-h2020/controller!157

- added exposition of redis-tests service for testing with Redis backend
- moved delete logic from Context Servicer to ORM components
- added support for constraints of different kinds