Static Analysis results ran from XCode 9.4.1

Ran Static analysis on my project and saw some collateral information that I thought I'd pass on.
I realize this is older code but probably still applies.

- OHHTTPStubs/OHHTTPStubs/Sources/OHHTTPStubs.m:46:1: Property of mutable type 'NSMutableArray' has 'copy' attribute; an immutable object will be stored instead

**Memory error Group**

- OHHTTPStubs/OHHTTPStubs/Sources/Mocktail/OHHTTPStubs+Mocktail.m:44:9: nil returned from a method that is expected to return a non-null value

- OHHTTPStubs/OHHTTPStubs/Sources/Mocktail/OHHTTPStubs+Mocktail.m:103:9: nil returned from a method that is expected to return a non-null value

- OHHTTPStubs/OHHTTPStubs/Sources/OHHTTPStubsResponse.m:153:12: nil passed to a callee that requires a non-null 1st parameter

### New Issue Checklist

- [NO ] I have tried with the latest version of OHHTTPStubs
- [YES ] I have read the [README](https://github.com/AliSoftware/OHHTTPStubs/blob/master/README.md)
- [ N/A] I have read the [Using the right Swift Version of `OHHTTPStubs` for your project](https://github.com/AliSoftware/OHHTTPStubs#using-the-right-swift-version-of-ohhttpstubs-for-your-project) section
- [NO ] I have searched in the [existing issues](https://github.com/AliSoftware/OHHTTPStubs/issues?utf8=✓&q=is%3Aissue)
- [ N/A] I have read [the OHHTTPStubs wiki](https://github.com/AliSoftware/OHHTTPStubs/wiki) to see if there wasn't a detailed page talking about my issue

### Environment

- version of OHHTTPStubs: [LIB VERSION HERE]
- integration method you are using:
* [ ] Cocoapods
* [ ] Carthage
* [ ] submodule
* [X ] other (*Built into our Project from sources)
- version of the tool you use: [5.1.0]

There is no ill issue seen with OHTTPStubs. This is just FYI in case you wish to investigate.
I realize this is an older version. I can't update and try again.