Move email template into ts file

[nfasulo]

TypeScript cannot be configured to copy arbitrary files into its output folder (microsoft/TypeScript#30835 (comment)), so the handlebars template for the welcome email is not being added to the dist folder. This leads to the following error in the compiled app:

UnhandledPromiseRejectionWarning: Error: ENOENT: no such file or directory, open '/home/node/dist/lib/emails/welcomeEmail.html.hbs'

In the future we can look into using another tool to give us a more flexible pipeline than TypeScript does, but for now the fastest solution is to move this template out of its own file and into the GovDeliveryClient.ts

I have left the directory lib/emails intact, but at this point neither of the templates it contains are being used by this app.

[rtravitz]

If I'm understanding the problem correctly, could we have Docker copy the arbitrary file for us, and would that even be preferable?

[kalilsn]

@rtravitz that's an interesting idea. I think it could work but we would also probably want to mount it in dist for local development. Probably not a huge issue at the moment but could get unwieldy if we end up with more static files in the future

[kalilsn]

@nfasulo if we go this route, could you also delete that lib/emails directory? 🚮

[kalilsn]

@nfasulo if we go this route, could you also delete that lib/emails directory? 🚮

[rtravitz]

This is now in the hot path for having this running after Dynamo got fixed. And the template string is dead simple to understand and change.