Bump base64 from 0.21.5 to 0.21.7 (#686)

Bumps [base64](https://github.com/marshallpierce/rust-base64) from 0.21.5 to 0.21.7.
- [Changelog](https://github.com/marshallpierce/rust-base64/blob/master/RELEASE-NOTES.md)
- [Commits](https://github.com/marshallpierce/rust-base64/compare/v0.21.5...v0.21.7)

---
updated-dependencies:
- dependency-name: base64
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Cargo.lock

@@ -179,9 +179,9 @@ dependencies = [
 
 [[package]]
 name = "base64"
-version = "0.21.5"
+version = "0.21.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "35636a1494ede3b646cc98f74f8e62c773a38a659ebc777a2cf26b9b74171df9"
+checksum = "9d297deb1925b89f2ccc13d7635fa0714f12c87adce1c75356b39ca9b7178567"
 
 [[package]]
 name = "bitflags"