band_gaps_he: inherit AcousticBandGapsApp from HomogenizationApp
band_gaps_he: inherit AcousticBandGapsApp from HomogenizationApp

- because of common options

sfepy/sfepy,vlukes/sfepy,rc/sfepy,RexFuzzle/sfepy,lokik/sfepy,sfepy/sfepy,RexFuzzle/sfepy,rc/sfepy,vlukes/sfepy,lokik/sfepy,RexFuzzle/sfepy,BubuLK/sfepy,BubuLK/sfepy,lokik/sfepy,lokik/sfepy,RexFuzzle/sfepy,BubuLK/sfepy,rc/sfepy,sfepy/sfepy,vlukes/sfepy