Bump h2 in /demos/remote_attestation/azure_attestation

Bumps [h2](https://github.com/hyperium/h2) from 0.3.13 to 0.3.18.
- [Release notes](https://github.com/hyperium/h2/releases)
- [Changelog](https://github.com/hyperium/h2/blob/master/CHANGELOG.md)
- [Commits](https://github.com/hyperium/h2/compare/v0.3.13...v0.3.18)

---
updated-dependencies:
- dependency-name: h2
  dependency-type: indirect
...

Signed-off-by: dependabot[bot] <support@github.com>

demos/remote_attestation/azure_attestation/maa_attestation/azure_att/Cargo.lock

@@ -224,9 +224,9 @@ dependencies = [
 
 [[package]]
 name = "h2"
-version = "0.3.13"
+version = "0.3.18"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "37a82c6d637fc9515a4694bbf1cb2457b79d81ce52b3108bdeea58b07dd34a57"
+checksum = "17f8a914c2987b688368b5138aa05321db91f4090cf26118185672ad588bce21"
 dependencies = [
  "bytes",
  "fnv",

demos/remote_attestation/azure_attestation/maa_init/init/Cargo.lock

@@ -212,9 +212,9 @@ dependencies = [
 
 [[package]]
 name = "h2"
-version = "0.3.13"
+version = "0.3.18"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "37a82c6d637fc9515a4694bbf1cb2457b79d81ce52b3108bdeea58b07dd34a57"
+checksum = "17f8a914c2987b688368b5138aa05321db91f4090cf26118185672ad588bce21"
 dependencies = [
  "bytes",
  "fnv",