* Adding bulk upgrade api

* Addressing comments

* Removing todo

* Changing body field

* Adding helper for getting the bulk install route

* Adding request spec

* Pulling in Johns changes

* Removing test for same package upgraded multiple times

* Adding upgrade to setup route

* Adding setup integration test

* Clean up error handling

* Beginning to add tests

* Failing jest mock tests

* Break up tests & modules for easier testing.

Deal with issue described in jestjs/jest#1075 (comment)

epm/packages/install has functions a, b, c which are independent but a can also call b and c

function a() {
  b();
  c();
}

The linked FB issue describes the cause and rationale (Jest works on "module" boundary) but TL;DR: it's easier if you split up your files

Some related links I found during this journey

 * https://medium.com/@qjli/how-to-mock-specific-module-function-in-jest-715e39a391f4
  * https://stackoverflow.com/questions/52650367/jestjs-how-to-test-function-being-called-inside-another-function
   * https://stackoverflow.com/questions/50854440/spying-on-an-imported-function-that-calls-another-function-in-jest/50855968#50855968

* Add test confirming update error result will throw

* Keep orig error. Add status code in http handler

* Leave error as-is

* Removing accidental code changes. File rename.

* Missed a function when moving to a new file

* Add missing type imports

* Lift .map lambda into named outer function

* Adding additional test

* Fixing type error

Co-authored-by: John Schulz <john.schulz@elastic.co>
Co-authored-by: Elastic Machine <elasticmachine@users.noreply.github.com>