fix(server): kneigbor-api has unmatched edge type with server

[LiJie20190102]

Purpose of the PR

• close fix(client): kneigbor-api has unmatched edge type with server incubator-hugegraph-toolchain#644

Main Changes

Verifying these changes

• Trivial rework / code cleanup without any test coverage. (No Need)
• Already covered by existing tests, such as (please modify tests here).
• Need tests and can be verified as follows:

graphs/graph_demo1/traversers/kneighbor
    {
	"countOnly": false,
	"limit": 10000000,
	"maxDepth": 1,
	"pathWithEdge": false,
	"steps": {
		"direction": "BOTH",
		"maxDegree": 1000,
		"skipDegree": 0,
		"vSteps": []
	},
	"withEdge": false,
	"withPath": true,
	"withVertex": false
}


**result:**

{
	"kneighbor": [
		"2:car1!2",
		"2:car2!4"
	],
	"size": 2,
	"paths": [
		{
			"objects": [
				"1:zhangsan",
				"2:car1!2"
			]
		},
		{
			"objects": [
				"1:zhangsan",
				"2:car2!4"
			]
		}
	],
	"vertices": [],
	"edges": []
}

graphs/graph_demo1/traversers/kneighbor
    {
	"countOnly": false,
	"limit": 10000000,
	"maxDepth": 1,
	"pathWithEdge": false,
	"steps": {
		"direction": "BOTH",
		"maxDegree": 1000,
		"skipDegree": 0,
		"vSteps": []
	},
	"withEdge": true,
	"withPath": true,
	"withVertex": true
}


**result:**

{
	"kneighbor": [
		"2:car1!2",
		"2:car2!4"
	],
	"size": 2,
	"paths": [
		{
			"objects": [
				"1:zhangsan",
				"2:car1!2"
			]
		},
		{
			"objects": [
				"1:zhangsan",
				"2:car2!4"
			]
		}
	],
	"vertices": [
		{
			"id": "2:car2!4",
			"label": "car",
			"type": "vertex",
			"properties": {
				"age": 4,
				"qsdi_task_id": "car2_task_id_test",
				"qsdi_record_id": "test_record_id",
				"name": "car2",
				"qsdi_data_source": "1"
			}
		},
		{
			"id": "1:zhangsan",
			"label": "people",
			"type": "vertex",
			"properties": {
				"age": 55,
				"qsdi_record_id": "926133154860048384",
				"name": "zhangsan",
				"qsdi_data_source": "1"
			}
		},
		{
			"id": "2:car1!2",
			"label": "car",
			"type": "vertex",
			"properties": {
				"age": 2,
				"qsdi_task_id": "car1_task_id_test",
				"qsdi_record_id": "car1_log_id_test",
				"name": "car1",
				"qsdi_data_source": "1"
			}
		}
	],
	"edges": [
		{
			"id": "S1:zhangsan>3>3>>S2:car2!4",
			"label": "driver_single",
			"type": "edge",
			"outV": "1:zhangsan",
			"outVLabel": "people",
			"inV": "2:car2!4",
			"inVLabel": "car",
			"properties": {
				"qsdi_task_id": "zhangsan_car2_rask_id_test",
				"qsdi_record_id": "926133802515111937",
				"name": "ride12",
				"driver_count": 23,
				"qsdi_data_source": "1"
			}
		},
		{
			"id": "S1:zhangsan>3>3>>S2:car1!2",
			"label": "driver_single",
			"type": "edge",
			"outV": "1:zhangsan",
			"outVLabel": "people",
			"inV": "2:car1!2",
			"inVLabel": "car",
			"properties": {
				"qsdi_record_id": "926133804008284160",
				"name": "ride88",
				"driver_count": 88,
				"qsdi_data_source": "1"
			}
		}
	]
}

Does this PR potentially affect the following parts?

• Dependencies (add/update license info & regenerate_known_dependencies.sh)
• Modify configurations
• The public API
• Other affects (typed here)
• Nope

Documentation Status

• Doc - TODO
• Doc - Done
• Doc - No Need

[LiJie20190102]

@imbajin Please help review it

[imbajin]

Good to see the tests meets expectations

[javeme]

looks like we cut the returning ids branch?
due to it is not easy for the client to determine whether it is an edge id or an edge object?

[javeme]

@LiJie20190102 Thank you for your contribution. please also change the api version to 0.72: https://github.com/apache/incubator-hugegraph/blob/master/hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/version/ApiVersion.java#L123