SwiftLint2

Add `/Application/Xcode-beta.app/…` to `LD_RUNPATH_SEARCH_PATHS` of SwiftLintFramework

By applying this, search paths will be following:
- Builded by Xcode.app # Homebrew build will be this.
```
@loader_path/Frameworks
/Application/Xcode.app/Toolchains/XcodeDefault.xctoolchain/usr/lib # Builded toolchain is first for debugging.
/Application/Xcode.app/Toolchains/XcodeDefault.xctoolchain/usr/lib # Duplicated, but no problems occurred by this.
/Application/Xcode-beta.app/Toolchains/XcodeDefault.xctoolchain/usr/lib # This works on Xcode beta image.
```
- Builded by Xcode-beta.app
```
@loader_path/Frameworks
/Application/Xcode-beta.app/Toolchains/XcodeDefault.xctoolchain/usr/lib # Builded toolchain is first for debugging.
/Application/Xcode.app/Toolchains/XcodeDefault.xctoolchain/usr/lib
/Application/Xcode-beta.app/Toolchains/XcodeDefault.xctoolchain/usr/lib # Duplicated,but no problems occurred by this.
```