Increment version number to 0.2.0

DESCRIPTION

 Package: simulateDCE
 Title: Simulate data for discrete choice experiments 
-Version: 0.1.2
+Version: 0.2.0
 Authors@R: 
     person(given = "Julian", family = "Sagebiel", email = "julian.sagebiel@idiv.de", role = c("aut", "cre"),
            comment = c(ORCID = "0000-0002-0253-6875"))

NEWS.md

+# simulateDCE 0.2.0
+
 # simulateDCE 0.1.2
 
 * This is the first release that works well and can be used by anyone. Look at the examples to see how it works.