solrium v1.0.0

This is v1, indicating breaking changes from the previous version!

NEW FEATURES

• Package has been reworked to allow control over what parameters are sent
  as query parameters and which as body. If only query parameters given, we do a
  GET request, but if any body parameters given (even if query params given)
  we do a POST request. This means that all solr_* functions have more or
  less the same parameters, and you now pass query parameters to params and
  body parameters to body. This definitely breaks previous code, apologies
  for that, but the bump in major version is a big indicator of the breakage.
• As part of overhaual, moved to using an R6 setup for the Solr connection
  object. The connection object deals with connection details, and you can call
  all methods on the object created. Additionally, you can simply
  pass the connection object to standalone methods. This change means
  you can create connection objects to >1 Solr instance, so you can use many
  Solr instances in one R session. (#100)
• gains new functions update_atomic_json and update_atomic_xml for doing
  atomic updates (#97) thanks @yinghaoh
• solr_search and solr_all gain attributes that include numFound,
  start, and maxScore (#94)
• solr_search/solr_all/solr_mlt gain new feature where we automically
  check for and adjust rows parameter for you if you allow us to.
  You can toggle this behavior and you can set a minimum number for rows
  to be optimized with minOptimizedRows. See (#102) (#104) (#105) for
  discussion. Thanks @1havran

MINOR IMPROVEMENTS

• Replaced httr with crul. Should only be noticeable with respect
  to specifying curl options (#98)
• Added more tests (#56)
• optimize renamed to solr_optimize (#107)
• now solr_facet fails better when no facet.* fields given (#103)

BUG FIXES

• Fixed solr_highlight parsing to data.frame bug (#109)