add spec for with_python_2_7 with an apostrophe in `cmd`
add spec for with_python_2_7 with an apostrophe in `cmd`

travis-ci/dpl,computology/dpl,testfairy/dpl,travis-ci/dpl,travis-ci/dpl,testfairy/dpl,testfairy/dpl,pengsrc/dpl