CRAN version 0.2.0

This release welcomes a new package author @jmaspons. The lists of changes here gives an overview of the amazing work he has contributed to this new major version.

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Major changes:

• New osmdata_data_frame() function to return non-spatial data.frame structures directly from overpass; thanks to @jmaspons (#285).
• Improved add_osm_features so that key-values pairs can be submitted as a list, rather than escape-delimited character strings; thanks to @elipousson (#277, #278).
• opq() can now utilise overpass ability to filter results by area; thanks to @jmaspons (#286).
• opq() now has additional "out" parameter to control the kinds of data returned by overpass; thanks to @jmaspons (#288).
• opq() now has additional "osm_types" parameter to provide finer control of which kinds of data are returned by overpass; thanks to @jmaspons (#295).
• sp dependency moved to suggested and added missing osmdata_* functions to docs; by @jmaspons & @mpadge (#302)
• Fix key modifications for non-valid column names and handle duplicated column names in osmdata_* functions; by @jmaspons (#303)
• @elipousson is new package contributor, thanks to the above work.
• @jmaspons is new package author, thanks to #285 (plus most of the above, and a whole lot more!)

Minor changes:

• Downgraded sp from "Imports" to "Suggests"; thanks to @jmaspons (#302)
• Improved osm_osm_id() to accept vectors of ids and types; thanks to @jmaspons (#268, #282, #283)
• "get-osmdata.R" file now split into several smaller and more manageable files (#306, thanks to @jmaspons)