login.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                System.out.println("Clicou");
                if(isValid()){
                    AndroidUtils.hideKeyboard(email, getActivity());
                    AuthenticationActivity.login(email.getText().toString(), password.getText().toString());
                }
            }
        });

login.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                System.out.println("Clicou");
                if(isValid()){
                    AndroidUtils.hideKeyboard(email, getActivity());
                    AuthenticationActivity instance = new AuthenticationActivity();
                    instance.login(email.getText().toString(), password.getText().toString());
                }
            }
        });