Add logging for invalid model errors (#126)

Add logging for invalid model errors

Co-authored-by: kolaente <k@knt.li>
Reviewed-on: https://kolaente.dev/vikunja/api/pulls/126

vendor/github.com/cweill/gotests/.travis.yml

@@ -0,0 +1,15 @@
+sudo: required
+language: go
+go:
+  - 1.9.x
+  - 1.10.x
+  - 1.11.x
+  - 1.12.x
+before_install:
+  - go get github.com/mattn/goveralls
+  - if ! go get github.com/golang/tools/cmd/cover; then go get golang.org/x/tools/cmd/cover; fi
+script:
+  - go test ./...
+  - go test -c -covermode=count -coverpkg=github.com/cweill/gotests,github.com/cweill/gotests/internal/input,github.com/cweill/gotests/internal/render,github.com/cweill/gotests/internal/goparser,github.com/cweill/gotests/internal/output,github.com/cweill/gotests/internal/models
+  - ./gotests.test -test.coverprofile coverage.cov
+  - $HOME/gopath/bin/goveralls -service=travis-ci -coverprofile=coverage.cov