[applyCoverage()](https://github.com/Microsoft/vscode-go/blob/4f33a078a8fd65dd9be763b213554501972641bb/src/goCover.ts#L117) does not work with files outside the $GOPATH. `coverageFiles` paths come from `go test`, which returns non-$GOPATH paths like `_/main.go`
applyCoverage() does not work with files outside the $GOPATH.
coverageFilespaths come fromgo test, which returns non-$GOPATH paths like_/main.go