Identity File not working
The new openssh version (7.0+) deprecated DSA keys and is not using DSA keys by default (not on server or client). The keys are not preferred to be used anymore, so if you can, I would recommend to use RSA keys where possible.

If you really need to use DSA keys, you need to explicitly allow them in your client config using

PubkeyAcceptedKeyTypes +ssh-dss


Should be enough to put that line in ~/.ssh/config, as the verbose message is trying to tell you. Ref.