Update to upstream API changes.

Changes in gopherjs/gopherjs@d9b5cb94dcecb1a655bff84b and gopherjs/gopherjs@4849c386217a149.
Fixes build, closes #4.

```
# github.com/go-on/gopherjslib
../src/github.com/go-on/gopherjslib/gopherjslib.go:201: s.ImportDependencies undefined (type *"github.com/gopherjs/gopherjs/build".Session has no field or method ImportDependencies)
../src/github.com/go-on/gopherjslib/gopherjslib.go:206: too many arguments in call to compiler.WriteProgramCode
```