Try to resolve #17, import / scope issue

[jeremiahpslewis]

Note: Ran tests locally and they all pass.

Test a fix to:

• 17

[jkrumbiegel]

Thank you, this was actually about a couple of wrong escapes, so I fixed it here https://github.com/jkrumbiegel/DataFrameMacros.jl/pull/20 Now it should also work if the functions transform etc. themselves are not exported