Dataverse: Do not require email server for development environments

[matthew-a-dunlap]

To install Dataverse, an email server is required to complete the installer. Dataverse will run without it (with some log errors) but the installer will not pass.

In the past I've hacked our installer to not ask for the email with good results, tho there may be some slowdown.

It would be good to make this optional for easier use of AWS environments, etc.

[djbrooke]

@matthew-a-dunlap - can you talk about this briefly in sprint planning tomorrow? Thank you!

[pameyer]

For future reference, something like http://nilhcem.com/FakeSMTP/ might be another approach to this.

[mheppler]

This came up today in a live demo. So embarrassing.

[pdurbin]

Please see also:

• issue #7236: When setting up a dev environment, I don't want to be blocked by not having a mail server
• pull request #7242: improve docs on setting up a new dev environment