Ditch pod in favor of spm, resolve warnings, update some deps, etc (#320)

* Ditch pod in favor of spm, resolve warnings, update some deps, etc

* Bump Xcode to 13.4 on CI

See if that fixes the Bitrise errors.

* ok commit the release of rswift we're using

Co-authored-by: Abizer Nasir <[email protected]>

Author: nickoneill

.circleci/config.yml

@@ -20,7 +20,7 @@ jobs:
     # The `macos` block requests that builds will run on a machine running
     # macOS with the specified version of Xcode installed
     macos:
-      xcode: '11.5.0'
+      xcode: '13.4.0'
     steps:
     # Machine Setup
     #   If you break your build into multiple jobs with workflows, you will probably want to do the parts of this that are relevant in each