Basic create support

[inlined]

This change adds support for firebase --open-sesame golang.

After running this command, firebase init will support Go 1.13
as a langauge for Cloud Functions.

Limitations:

1. .gitignore is empty
2. Customers cannot mix Node and Go code (WAI)
3. There is little validation being done of customer code
4. The actual deployed function params are hard coded; SDK incoming

[inlined]

❯ firebase init

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You're about to initialize a Firebase project in this directory:

  /Users/inlined/git/go-junkdrawer

? Which Firebase features do you want to set up for this directory? Press Space to select features, then Enter to confirm your choi
ces. Functions: Configure a Cloud Functions directory and its files

=== Project Setup

First, let's associate this project directory with a Firebase project.
You can create multiple project aliases by running firebase use --add,
but for now we'll just set up a default project.

i  .firebaserc already has a default project, using inlined-junkdrawer.

=== Functions Setup

A functions directory will be created in your project with sample code
pre-configured. Functions can be deployed with firebase deploy.

? What language would you like to use to write Cloud Functions? Go
? What would you like to name your module? acme.com/functions
go get: added firebase.google.com/go/v4 v4.6.0
✔  Wrote functions/go.mod
✔  Wrote functions/functions.go
✔  Wrote functions/.gitignore

i  Writing configuration info to firebase.json...
i  Writing project information to .firebaserc...

✔  Firebase initialization complete!

❯ firebase deploy

=== Deploying to 'inlined-junkdrawer'...

i  deploying functions
i  functions: ensuring required API cloudfunctions.googleapis.com is enabled...
i  functions: ensuring required API cloudbuild.googleapis.com is enabled...
✔  functions: required API cloudfunctions.googleapis.com is enabled
✔  functions: required API cloudbuild.googleapis.com is enabled
i  functions: preparing functions directory for uploading...
i  functions: packaged functions (15.93 KB) for uploading
✔  functions: functions folder uploaded successfully
i  functions: creating Go 1.13 function HelloWorld(us-central1)...
✔  functions[HelloWorld(us-central1)]: Successful create operation.
Function URL (HelloWorld(us-central1)): https://us-central1-inlined-junkdrawer.cloudfunctions.net/HelloWorld

✔  Deploy complete!

Project Console: https://console.firebase.google.com/project/inlined-junkdrawer/overview