Adding tests to increase coverage for stateful expression test
Adding tests to increase coverage for stateful expression test

* Supplied reference doesn't exists in BinaryNode{RefNode, NumNode}
* BinaryNode{RefNode,NumNode} value is changed
* BinaryNode{RefNode,NumNode} type is changed from float64 to int64
* BinaryNode{BinaryNode{RefNode,NumNode}, BinaryNode{RefNode,NumNode}}
sputnik13/kapacitor,yosiat/kapacitor,yosiat/kapacitor,sputnik13/kapacitor,muxinc/kapacitor,titilambert/kapacitor,influxdata/kapacitor,muxinc/kapacitor,influxdb/kapacitor,yosiat/kapacitor,bbczeuz/kapacitor,influxdb/kapacitor,muxinc/kapacitor,influxdata/kapacitor,influxdata/kapacitor,adityacs/kapacitor,adityacs/kapacitor,titilambert/kapacitor,sputnik13/kapacitor,bbczeuz/kapacitor,titilambert/kapacitor,adityacs/kapacitor,bbczeuz/kapacitor,influxdb/kapacitor