CRAN release

genderizeR 2.0.0

• parallel processing in genderizeTrain works properly under Linux now
• simple solution for caching results for findGivenNames()
• fix in misspelled name function (classificationErrors)
• small improvement in textPrepare() function
• updated and corrected help pages and function examples
• more comprehensive exemplary datasets description
• new more comprehensive set of unit tests
• small fixes and code cleaning
• more thorough unit tests
• updated README file
• added tutorial vignette