travis: try installing boost from apt
travis: try installing boost from apt

alexfrolov/grappa,uwsampa/grappa,uwsampa/grappa,buaasun/grappa,buaasun/grappa,alexfrolov/grappa,uwsampa/grappa,uwsampa/grappa,alexfrolov/grappa,alexfrolov/grappa,uwsampa/grappa,buaasun/grappa,buaasun/grappa,alexfrolov/grappa,uwsampa/grappa,alexfrolov/grappa,buaasun/grappa,buaasun/grappa,alexfrolov/grappa,buaasun/grappa,uwsampa/grappa