[gomod] Bump github.com/Knetic/govaluate from 0.0.0-20171022003610-9aa49832a739 to 3.0.0+incompatible

[gomod] Bump github.com/Knetic/govaluate from 0.0.0-20171022003610-9aa49832a739 to 3.0.0+incompatible #238