* enable to set a function to entry option
* add tests for entry function
* fix style
* fix identifier and readableIdentifier of MultiModule
* use arrow functions
* use arrow function
* remove incorrect new operators
* fix Validation tests
* es5->es6 refactoring of SingleEntryPlugin
Added unit test for the testing of said plugin
* Forgot to switch coding styles back to tabs.
* trying to please the linting gods.
* removing the output property per suggestion