Performance Improvements (#199)

Modifications:
- Replace `HTTPHandler` with `NIOHTTPClientResponseAggregator`, to fix a CoW issue. This increases performance.
- Ensure that we only use one `EventLoop` in tests.
- Use `syncOperations` to setup the `HTTPClient`.

Author: fabianfett

Package.swift

@@ -15,7 +15,7 @@ let package = Package(
         .library(name: "AWSLambdaTesting", targets: ["AWSLambdaTesting"]),
     ],
     dependencies: [
-        .package(url: "https://github.com/apple/swift-nio.git", .upToNextMajor(from: "2.17.0")),
+        .package(url: "https://github.com/apple/swift-nio.git", .upToNextMajor(from: "2.26.0")),
         .package(url: "https://github.com/apple/swift-log.git", .upToNextMajor(from: "1.0.0")),
         .package(url: "https://github.com/swift-server/swift-backtrace.git", .upToNextMajor(from: "1.1.0")),
     ],

scripts/soundness.sh

@@ -19,7 +19,7 @@ here="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
 
 function replace_acceptable_years() {
     # this needs to replace all acceptable forms with 'YEARS'
-    sed -e 's/2017-2018/YEARS/' -e 's/2017-2020/YEARS/' -e 's/2019/YEARS/' -e 's/2020/YEARS/'
+    sed -e 's/2017-2018/YEARS/' -e 's/2017-2020/YEARS/' -e 's/2017-2021/YEARS/' -e 's/2019/YEARS/' -e 's/2020/YEARS/'
 }
 
 printf "=> Checking for unacceptable language... "