Adding helm2 install step (#406)

Author: bnookala

src/lib/fileutils.ts

@@ -546,6 +546,12 @@ const manifestGenerationPipelineYaml = (): string => {
         persistCredentials: true,
         clean: true
       },
+      {
+        task: "HelmInstaller@1",
+        inputs: {
+          helmVersionToInstall: "2.16.3"
+        }
+      },
       {
         script: generateYamlScript([
           `# Download build.sh`,

src/test/mockFactory.ts

@@ -399,6 +399,12 @@ export const createTestHldAzurePipelinesYaml = (
         persistCredentials: true,
         clean: true
       },
+      {
+        task: "HelmInstaller@1",
+        inputs: {
+          helmVersionToInstall: "2.16.3"
+        }
+      },
       {
         script: generateYamlScript([
           `# Download build.sh`,

src/types.d.ts

@@ -130,7 +130,8 @@ export interface AzurePipelinesYaml {
       VERIFY_ONLY?: number;
     };
     inputs?: {
-      scriptPath: string;
+      scriptPath?: string;
+      helmVersionToInstall?: string;
     };
     persistCredentials?: boolean;
     script?: string;