Update base64 requirement from 0.21.0 to 0.22.0 (#592)

Updates the requirements on [base64](https://github.com/marshallpierce/rust-base64) to permit the latest version.
- [Changelog](https://github.com/marshallpierce/rust-base64/blob/master/RELEASE-NOTES.md)
- [Commits](marshallpierce/rust-base64@v0.21.2...v0.22.0)

---
updated-dependencies:
- dependency-name: base64
  dependency-type: direct:production
...

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

Cargo.toml

@@ -19,7 +19,7 @@ targets = ["x86_64-unknown-linux-gnu"]
 [dependencies]
 async-trait = "0.1.50"
 arc-swap = "1.3.0"
-base64 = "0.21.0"
+base64 = "0.22.0"
 bytes = "1.0.1"
 chrono = { version = "0.4.19", default-features = false, features = [
     "serde",
@@ -63,7 +63,7 @@ tokio = { version = "1.17.0", default-features = false, features = [
 tokio-test = "0.4.2"
 wiremock = "0.6.0"
 crypto_box = { version = "0.8.2", features = ["seal"] }
-base64 = "0.21.2"
+base64 = "0.22.0"
 pretty_assertions = "1.4.0"
 graphql_client = "0.13.0"