Added DateTime to events.

Added a DateTime field member to events to add the option to create events with a different start and stop times oher than DateTime.Now.
Added empty ctro that broke the build.
Event member names changed to match convention.
Merge pull request #16 from someuser77/events-with-time

Added DateTime to events.
MimeTypes type extended and made public.
Added mimeType argument to WriteText method.
Refactored.
File writing methods renamed to overload.
Sting to binary conversion and assembly names.

Added Attachments.ToBinary method calls to convert strings to UTF8 byte arrays.

Added abstarct member AssemblyName to BaseBehaviorWeaver and implemented in all behaviors.

Aded convenience methods to BaseBehaviorWeaver.
Implemented NUnitAttachmentWeaver.
Create appveyor.yml
Update appveyor.yml
Update appveyor.yml
Update appveyor.yml
Update README.md
Update appveyor.yml
Merge branch 'master' into weaver
Merge branch 'weaver' of https://github.com/someuser77/allure-csharp-commons into weaver