add vim files to .gitignore

https://github.com/github/gitignore/blob/f0f5e38db20332f55b95d938a55e98ae9b05bb3d/Global/vim.gitignore
add callink_id field to events
cucumber test for Event.saveCallinkEvent

admittedly this should be an rspec test because we are not doing
integration testing the application but doing unit-test like testing but
we are trying to meet an weekly 3 cucumber test requirement