Add warning to CHANGES.md regarding Dagger 1.2.0 upgrade.
Add warning to CHANGES.md regarding Dagger 1.2.0 upgrade.

didvae/feign,OpenFeign/feign,FrEaKmAn/feign,jmnarloch/feign,olkulyk/feign,didvae/feign,zhoupan/feign,olkulyk/feign,Echo19890615/feign,spencergibb/feign,Netflix/feign,Netflix/feign,OpenFeign/feign,openedbox/feign,spencergibb/feign,gorcz/feign,bstick12/feign,gorcz/feign,prembasumatary/feign,OpenFeign/feign,prembasumatary/feign,ddteeter/feign,bstick12/feign,FrEaKmAn/feign,ddteeter/feign,jmnarloch/feign,openedbox/feign,zhoupan/feign,Echo19890615/feign