remove python 2.7 tests from travis config
remove python 2.7 tests from travis config

simonvh/gimmemotifs,simonvh/gimmemotifs,simonvh/gimmemotifs,simonvh/gimmemotifs,simonvh/gimmemotifs,simonvh/gimmemotifs,simonvh/gimmemotifs