v0.4.1

For the most part implemented spec changes. Now compatible with "October 2015" version of the GraphQL spec.

• Type condition optional on inline fragments. (#82) (spec change)

• Make operation name optional (#81) (spec change)

• Introspection descriptions for scalars and introspection (#80)

• beforeField now able to replace value and prevent resolve call (#79). This can be useful for things like caching. It contains minor breaking change - return type of beforeField has changed. If you are implementing it, just return continue if your FieldVal was Unit or continue(someFieldVal).

• Projection and NoProjection should be tags instead of resolve function wrappers (#78). Backwards-incompatible change: you need to replace
  Projection with ProjectionName tag and NoProjection with ProjectionExclude tag. here is an example:

  // before
  
  Field("id", StringType,
    Some("The id of the droid."),
    resolve = Projection("_id", _.value.id)),
  
  // after
  
  Field("id", StringType,
    Some("The id of the droid."),
    tags = ProjectionName("_id") :: Nil,
    resolve = _.value.id)