## Motivation:
There is no way to run code statically like in Obj-C using `+ [NSObject initialize]`, so this ensures (through a new `SwiftLint` rule) that all test classes inherit this common test class instead of `XCTestCase` directly.
A future PR will make use of this new `CIRCLECI_TESTS_GENERATE_SNAPSHOTS` environment variable to allow regenerating snapshots in CI.
I've also moved the duplicated `CurrentTestCaseTracker` usages to a single point.
This is a special enough error that it's worth distinguishing from other `ErrorCode.networkError`s.
I see a couple benefits:
- When opening an app that has the SDK, this used to print lots of errors that just said "Error performing request". Now it's more clear what's happening
- Users can respond to failed calls to the SDK more appropriately, whereas before it might not be clear why a request failed.
Also fixed `logErrorIfNeeded` not passing the file/function/line parameters to the log functions.
* moved test suites to Tests folder
* fixed outdated path
* fixed more outdated paths
* moved TestsPlans to Tests folder
* update path to Constants.swift
Joshua Liebowitz