websocket message length too small

[vladkras]

Currently websocket message is limited to 8192 bytes:

gremgo/connection.go

Lines 51 to 52 in f9215ff

	WriteBufferSize: 8192,
	ReadBufferSize: 8192,

this is definitely not enough for any serious management system and causes nasty errors on gremlin side:

gremlin_1  | [WARN] AbstractGraphSONMessageSerializerV2d0 - Request [PooledUnsafeDirectByteBuf(ridx: 8175, widx: 8175, cap: 8192)] could not be deserialized by org.apache.tinkerpop.gremlin.driver.ser.AbstractGraphSONMessageSerializerV2d0.
gremlin_1  | org.apache.tinkerpop.shaded.jackson.core.io.JsonEOFException: Unexpected end-of-input in character escape sequence
gremlin_1  |  at [Source: (byte[])"{"requestId":"44a7bc13-f7f4-4731-bd68-df6cab6b988b","op":"eval","processor":"","args":{"bindings":{"_0":"Grimis-long-label","_1":"long","_2":"\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u00"[truncated 7675 bytes]; line: 1, column: 16351]

Increasing this settings fixes the error, so we're preparing a MR making gremgo.NewDialer() more flexible with the possibility to set more websocket.Dialer options