Mismatch of API

Hi all,

When I run
```
$ kubectl create -f deploy/katlas-service.yaml
```
I got a error

```
$ kubectl logs -f katlas-service-58b8bcf9c4-h9bvd
time="2019-11-27T06:47:21Z" level=info msg="EnvNamespace="
time="2019-11-27T06:47:21Z" level=info msg="ServerType=http"
time="2019-11-27T06:47:21Z" level=info msg="DgraphHost=dgraph-public:9080"
time="2019-11-27T06:47:21Z" level=info msg="Connecting to dgraph [dgraph-public:9080]"
time="2019-11-27T06:47:21Z" level=info msg="LRU cache created with given size"
time="2019-11-27T06:47:21Z" level=info msg="Starting initialize schema and metadata... "
time="2019-11-27T06:47:21Z" level=error msg="Query[{objects (func:eq(name,\"application\")) @filter(eq(objtype,\"metadata\")) {count(uid)}}] Error [rpc error: code = Internal desc = grpc: error unmarshalling request: proto: wrong wireType = 2 for field StartTs]\n"
time="2019-11-27T06:47:21Z" level=debug msg="rpc error: code = Internal desc = grpc: error unmarshalling request: proto: wrong wireType = 2 for field StartTs"
panic: interface conversion: interface {} is nil, not []interface {}

goroutine 1 [running]:
main.serve()
/home/travis/gopath/src/github.com/intuit/katlas/service/.gopath~/src/github.com/intuit/katlas/service/server.go:115 +0x2ee3
main.main()
/home/travis/gopath/src/github.com/intuit/katlas/service/.gopath~/src/github.com/intuit/katlas/service/server.go:141 +0x18b

```

Start with deploy/katlas-service.yaml to reproduce the deployment, then inspect service/server.go around line 115 where initialization panics. Compare the Dgraph request path and the reported protobuf wire-type error to identify the API mismatch. Done means the service initializes without the unmarshalling error or nil-interface panic.

Written by the indexing model from the issue text.