Initial implementation of Aite.

[robshakir]

 * (A) Dockerfile.aite
   - Dockerfile to build Aite. This implementation requires
     kernel-level privileges, which can be added through
     --privileged, but --cap-add NET_ADMIN may be sufficient (for
     Docker), requires additional examination.
 * (A) srv/srv.go
   - Initial server implementation of Aite.
 * (A) proto/aite
   - Protobuf gRPC API for Aite. This interface allows a test to
     interface with Aite.
 * (A) cmd/aite
   - Binary acting as the Aite main.

To add:

• Some form of testing -- likely in the form of an e2e test that can
  validate functionality integrates with the kernel since there is
  limited package logic here.

[robshakir]

Revised API examples:

➜  ~ grpcurl -plaintext -d '{"name": "eth0", "params": {"state": "IS_UP", "latency_msec": 64,  "loss_pct": 10 }}' localhost:60061 openconfig.aite.Aite.SetInterface
{
  "name": "eth0",
  "params": {
    "state": "IS_UP",
    "latencyMsec": 64,
    "lossPct": 10
  }
}

➜  ~ grpcurl -plaintext -d '{"name": "eth0", "params": {"state": "IS_UP", "latency_msec": 0,  "loss_pct": 0 }}' localhost:60061 openconfig.aite.Aite.SetInterface
{
  "name": "eth0",
  "params": {
    "state": "IS_UP"
  }
}

[robshakir]

Confirmed that we just need to use --cap-add NET_ADMIN rather than --privileged. I believe kind will give us more permissions than this, since we create interfaces within those pods in KNE, but to be validated.

[robshakir]

Leaving open for @akrentsel and @alshabib to take a look before submitting.