fix problem with cashier tests

Merge pull request #8 from rbanks54/cashier_cleanup

add barista domain specific event for order started to avoid problem of republishing cashier domain event

renamed barista order domain object to avoid clash with cashier order

fixed a typo on ES port number and updated nuget packages

fixed a typo in a command DTO

add event listeners in cashier and barista

add test for creating a barista's order when cashier places one

get barista service compiling

wip - hacking on the barista service

Fixing Barista service as well

validate product code when starting a new order

add local representation of products to the cashier domain

add a few unit tests

Update README.md