Reword comment & finish deprecation of old version argument

action.yml

@@ -4,7 +4,7 @@ author: 'GitHub'
 branding:
   icon: play
   color: green
-inputs: 
+inputs:
   dotnet-version:
     description: 'SDK version to use. Examples: 2.2.104, 3.1, 3.1.x'
   source-url:
@@ -13,10 +13,6 @@ inputs:
     description: 'Optional OWNER for using packages from GitHub Package Registry organizations/users other than the current repository''s owner. Only used if a GPR URL is also provided in source-url'
   config-file:
     description: 'Optional NuGet.config location, if your NuGet.config isn''t located in the root of the repo.'
-  # Deprecated option, do not use. Will not be supported after October 1, 2019
-  version:
-    description: 'Deprecated. Use dotnet-version instead. Will not be supported after October 1, 2019'
-    deprecationMessage: 'The version property will not be supported after October 1, 2019. Use dotnet-version instead'
 runs:
   using: 'node12'
   main: 'dist/index.js'

src/setup-dotnet.ts

@@ -7,13 +7,13 @@ import * as auth from './authutil';
 export async function run() {
   try {
     //
-    // Version is optional.  If supplied, install / use from the tool cache
-    // If not supplied then task is still used to setup proxy, auth, etc...
+    // dotnet-version is optional, but needs to be provided for most use cases.
+    // If supplied, install / use from the tool cache.
+    // If not supplied, look for version in ./global.json.
+    // If a valid version still can't be identified, nothing will be installed.
+    // Proxy, auth, (etc) are still set up, even if no version is identified
     //
-    let version: string = core.getInput('version');
-    if (!version) {
-      version = core.getInput('dotnet-version');
-    }
+    let version = core.getInput('dotnet-version');
     if (!version) {
       // Try to fall back to global.json
       core.debug('No version found, trying to find version from global.json');