Greenmask 0.2.9

This release introduces a new transformer and fixes some bug.

Changes

Implemented RandomCompany transformer - it's a multi-column transformer, that generates a company data with attributes CompanyName and CompanySuffix
#273 #274.
Fixed a case when transformers with column containers were not printed on greenmask list-transformers command
call #275.
Fixed RandomEmail transformer bug when an incorrect buffer size for hex-encoded symbols resulted in a \0 appearing in the string #278.
Fixed typo in database_subset.md docs #271
Revised README.md #280