Creates a DataFrame from a csv file. Header is a boolean indicating if the
file contains a header. If header is false, simple column names will be
generated.

Valid options are the same as clojure.data.csv:
   :separator (default \,)
   :quote (default \")

Creates a csv file from a DataFrame. Header is a boolean indicating if the
first line of the file should be column names.

Valid options are the same as clojure.data.csv:
   :separator (Default \,)
   :quote (Default \")
   :quote? (A predicate function which determines if a string should be quoted. Defaults to quoting only when necessary.)
   :newline (:lf (default) or :cr+lf)