CRAN release 0.2.0

What's Changed

• update by @ilovemane in #50
• expand mockCdmFromTables to support condition_occurrence and other tables by @catalamarti in #63
• mock_drug_exposure by @ilovemane in #56
• update addConcept by @ilovemane in #66
• changes by @ilovemane in #67
• Update DESCRIPTION by @ilovemane in #68
• Update DESCRIPTION by @ilovemane in #69
• Mock vocab by @ilovemane in #72
• Increment version number to 0.2.0 by @ilovemane in #73

Full Changelog: v0.1.0...v0.2.0