* adds config parsing and feeds to database at server start

* removes redundency on config reloads

* agent: implements logic to register agents and scan images and upload reports (#90)

* adds logic to register the agent and poll

* adds field scanner in policies

* adds field scanner in scans tables and updates test cases across

* adds foreign key integrationID to table scans and updates test cases

* adds field scanner in config yaml and supporting logic, adds enum for status fields

* adds field scanner in config yaml and supporting logic, adds enum for status fields

* updates logic to add an image:tag string in scans.image and integrationID in scans.integrationsID rendering its value using policy.image.registery which is equivalent to integrations.name

* fix executing of migration just once at the start of config loads

* restructure code for v0

* updates the get list call logic i.e orders by created_at ASC and adds its test case

* modularizing registries like dockerhub, gcr

* updates scan.Report logic to hold the json result of scanner

* modularizes the scanner tools

* modularizes the scanner tools

* some todo

* updates the get call to query by status

* updates the CRUD to use pointers as  certain fields are optional or conditionally updated

* agent implementation workflow

* assigner: implements task assignment for scans and dummy mock test (#95)

* updates the get call of scan to query by status

* updates the GET call of agents to query by status

* updates the GET call of agents to query by status or scan_id

* adds task assignment logic

* adds task assignment logic

* fix lints

* fix lints