Set default CEF version number and convert to int according to specif…

…ication (pcktdmp#27)

Add go.sum (pcktdmp#26)

* Add go.sum

Update go.mod with correct module references (pcktdmp#24)

* update example code in README

* update the go.mod file with correct references and remove old dep

Update example code in README (pcktdmp#23)

Add support for generating a log message to stdout (pcktdmp#19)

* add support for generating a log message to stdout

* update README

Expand and improve tests (pcktdmp#17)

* add more test cases
* set global base event for tests

Loop over mandatory fields and verify their content (pcktdmp#15)

Simple input checking for event generation (pcktdmp#14)