v0.1.0

• New fmi_split_long_query() can be used to split queries that are too long
  for their type into multiple shorter queries that fit (cf. #2).

• fmi_query() is now vectorised with respect to the query parameters. This
  means you can now (for example) simultaneously create queries for multiple
  places like fmi_query(place = c("Oulu", "Espoo")).

• fmi_data() now:

  1. Takes vectorized queries and returns the result in a single tbl_df. It
     is not advisable to mix query types (e.g. "daily" and "monthly") in
     a single query vector as that will result in malformed data.
  2. Recognizes when queries span a time interval too long for the type and
     automatically splits them with fmi_split_long_query().
  3. Adds a column to its output data specifying the place in the query.

• You can now use the environment variable FMIR_API_KEY to remember your API
  key across sessions.