feat(deploy-contract): deploygen does codegen only (WIP)

currently fails:

```
$ ./scripts/deploy-contract.js --deploygen src/sell-concert-tickets.js
(Error#1)
Error#1: ENOENT: no such file or directory, open 'src/auto-deploy.template.js'

  at async generateDeployArtifact (file:///home/connolly/projects/dapp-agoric-basics/contract/scripts/deploy-contract.js:70:20)
  at async main (file:///home/connolly/projects/dapp-agoric-basics/contract/scripts/deploy-contract.js:130:7)
```

contract/scripts/deploy-contract.js

@@ -18,6 +18,7 @@ const options = {
   service: { type: 'string', default: 'agd' },
   workdir: { type: 'string', default: '/workspace/contract' },
   deploy: { type: 'string', multiple: true },
+  deploygen: { type: 'string', multiple: true },
 };
 /**
  * @typedef {{
@@ -27,6 +28,7 @@ const options = {
  *   service: string,
  *   workdir: string,
  *   deploy: string[],
+ *   deploygen?: string[],
  * }} DeployOptions
  */
 
@@ -120,6 +122,15 @@ const main = async (bundleDir = 'bundles') => {
 
   const stem = path => basename(path).replace(/\..*/, '');
 
+  if (flags.deploygen) {
+    for (const contractEntry of flags.deploygen) {
+      const name = stem(contractEntry);
+      const generatedCoreEval = `bundles/deploy-${name}-entry.js`;
+      // TODO: fix
+      await generateDeployArtifact(generatedCoreEval, name, fsp);
+    }
+  }
+
   // deploy in one step
   if (flags.deploy) {
     for await (const contractEntry of flags.deploy) {