Project does not build anymore

When I type `make` the following output:

```
go build -ldflags "-X github.com/protocollabs/mapago/core.BuildVersion=1cd2689 -X github.com/protocollabs/mapago/core.BuildDate=2019-01-11T21:28:56+0100" -o mapago cmd/mapago/mapago.go
stat cmd/mapago/mapago.go: no such file or directory
make: *** [Makefile:19: mapago] Error 1
```