Do not guess type = any, potentially provide opt-in

[peterdesmet]

CHANGELOG: https://datapackage.org/overview/changelog/#any-field-type-updated

any is now the default field type and clarifies that the field type should not be inferred if not provided (#13).

In case of CSV files, values should therefore be interpreted as a string. read_resource() however, currently mimics readr::read_delim() default behaviour of guessing the data type of a column when it is undefined (i.e. no type property is provided). read_delim() allows to turn of that behaviour (by specifying col_types).

Reverting to strings for any (= and thus also not provided types) may have a big impact to users, so maybe read_resource() should provide a col_guess argument with default FALSE., and should only be done for v2 (see #226).

• Implement changes
• Update documentation
• Update tests