ChangeLog

2013-06-15 - version 0.1:
   - Initial release
2013-10-19 - version 0.2:
   - Fixes bugs on extract.tweets
   - Adds ideology estimation and plots
   - Adds functions to get friends and followers with multiple OAuth tokens
2014-01-22 - version 0.3:
    - Added option to query by date
2014-02-22 - version 0.3.1:
    - added multiple keywords
    - remove private info from documentation
    - updated documentation to changes in code
2014-03-11 - version 0.3.2:
    - added getList function
    - added query by user in mongoDB
2014-04-15 - version 0.3.3:
    - added function to dump tweets on MongoDB
2014-05-01 - version 0.3.4:
    - query tweets from multiple users
2014-07-15 - version 0.3.5:
    - fixed errors in function that formats date
    - added getStatuses function for bulk download of tweets
2014-08-14 - version 0.3.6:
    - new link to twofishes geocoder
2015-10-13 - version 0.4:
    - new function: getRetweets, getUsersBatch, searchUsers
    - some functions now work with httr
    - general bug fixes
2016-01-01 - version 0.5:
    - new function: searchTweets
    - better verbose messages
    - fixes bug in getUsersBatch function
    - improves dependencies