Remove support for Swift 5.1

Package.swift

@@ -1,4 +1,4 @@
-// swift-tools-version:5.1
+// swift-tools-version:5.2
 //===----------------------------------------------------------------------===//
 //
 // This source file is part of the SwiftNIO open source project
@@ -31,10 +31,41 @@ let package = Package(
         .package(url: "https://github.com/apple/swift-crypto.git", from: "1.0.0"),
     ],
     targets: [
-        .target(name: "NIOSSH", dependencies: ["NIO", "NIOFoundationCompat", "Crypto"]),
-        .target(name: "NIOSSHClient", dependencies: ["NIO", "NIOSSH", "NIOConcurrencyHelpers"]),
-        .target(name: "NIOSSHServer", dependencies: ["NIO", "NIOSSH", "NIOFoundationCompat", "Crypto"]),
-        .target(name: "NIOSSHPerformanceTester", dependencies: ["NIO", "NIOSSH", "Crypto"]),
-        .testTarget(name: "NIOSSHTests", dependencies: ["NIOSSH", "NIO", "NIOFoundationCompat"]),
+        .target(
+            name: "NIOSSH",
+            dependencies: [
+                .product(name: "NIO", package: "swift-nio"),
+                .product(name: "NIOFoundationCompat", package: "swift-nio"),
+                .product(name: "Crypto", package: "swift-crypto")
+            ]),
+        .target(
+            name: "NIOSSHClient",
+            dependencies: [
+                "NIOSSH",
+                .product(name: "NIO", package: "swift-nio"),
+                .product(name: "NIOConcurrencyHelpers", package: "swift-nio")
+            ]),
+        .target(
+            name: "NIOSSHServer",
+            dependencies: [
+                "NIOSSH",
+                .product(name: "NIO", package: "swift-nio"),
+                .product(name: "NIOFoundationCompat", package: "swift-nio"),
+                .product(name: "Crypto", package: "swift-crypto")
+            ]),
+        .target(
+            name: "NIOSSHPerformanceTester",
+            dependencies: [
+                "NIOSSH",
+                .product(name: "NIO", package: "swift-nio"),
+                .product(name: "Crypto", package: "swift-crypto")
+            ]),
+        .testTarget(
+            name: "NIOSSHTests",
+            dependencies: [
+                "NIOSSH",
+                .product(name: "NIO", package: "swift-nio"),
+                .product(name: "NIOFoundationCompat", package: "swift-nio")
+            ]),
     ]
 )

README.md

@@ -10,6 +10,8 @@ There are a number of reasons to provide a programmatic SSH implementation. One
 
 Another good reason to provide programmatic SSH is that it is not uncommon for services to need to interact with other services in a way that involves running commands. While `Process` solves this for the local use-case, sometimes the commands that need to be invoked are remote. While `Process` could launch an `ssh` client as a sub-process in order to run this invocation, it can be substantially more straightforward to simply invoke SSH directly. This is [`libssh2`](https://www.libssh2.org)'s target use-case. SwiftNIO SSH provides the equivalent of the networking and cryptographic layer of libssh2, allowing motivated users to drive SSH sessions directly from within Swift services.
 
+SwiftNIO SSH requires Swift 5.2 and newer. Older versions (0.2.x and above) support Swift 5.1.
+
 ## What does SwiftNIO SSH support?
 
 SwiftNIO SSH supports SSHv2 with the following feature set:

docker/Dockerfile

@@ -1,5 +1,5 @@
-ARG swift_version=5.1
-ARG ubuntu_version=bionic
+ARG swift_version=5.2
+ARG ubuntu_version=xenial
 ARG base_image=swift:$swift_version-$ubuntu_version
 FROM $base_image
 # needed to do again after FROM due to docker limitation

docker/docker-compose.1604.51.yaml → docker/docker-compose.1604.52.yaml

@@ -3,17 +3,17 @@ version: "3"
 services:
 
   runtime-setup:
-    image: swift-nio-ssh:16.04-5.1
+    image: swift-nio-ssh:16.04-5.2
     build:
       args:
         ubuntu_version: "xenial"
-        swift_version: "5.1"
+        swift_version: "5.2"
 
   test:
-    image: swift-nio-ssh:16.04-5.1
+    image: swift-nio-ssh:16.04-5.2
     environment:
       - SANITIZER_ARG=--sanitize=thread
       #- WARN_AS_ERROR_ARG=-warnings-as-errors
 
   shell:
-    image: swift-nio-ssh:16.04-5.1
+    image: swift-nio-ssh:16.04-5.2