overriding virtual functions wihtout keyword override

clang-6 is a bit more picky... here are the warnings I found...

/builds/pdelab/dune-pdelab/dune/pdelab/solver/newtonterminate.hh:39:18: warning: 'setParameters' overrides a member function but is not marked 'override' [-Winconsistent-missing-override]
    virtual void setParameters(const ParameterTree& parameterTree){

/builds/pdelab/dune-pdelab/dune/pdelab/solver/newtonlinesearch.hh:43:18: warning: 'setParameters' overrides a member function but is not marked 'override' [-Winconsistent-missing-override]
    virtual void setParameters(const ParameterTree&) {}

/builds/pdelab/dune-pdelab/dune/pdelab/solver/newtonlinesearch.hh:169:18: warning: 'setParameters' overrides a member function but is not marked 'override' [-Winconsistent-missing-override]
    virtual void setParameters(const ParameterTree& parameterTree)