Add "go-callvis" program to Go Tools section. (#1251)
Add "go-callvis" program to Go Tools section. (#1251)

go-callvis is a development tool to help visualize call graph of your Go program using Graphviz's dot format.
jmelfi/awesome-go,hvnsweeting/awesome-go,pconcepcion/awesome-go,abhishekgahlot/awesome-go,avelino/awesome-go,theckman/awesome-go,joeybloggs/awesome-go,sadlil/awesome-go,subodhchhabra/awesome-go,chrislusf/awesome-go,bscott/awesome-go,Oire/awesome-go