New feed version notification only applies to fetch method

[landonreed]

There are a handful of methods to create a new version (fetch, upload, create from snapshot), but the only one that triggers an email notification is the fetch method.

datatools-server/src/main/java/com/conveyal/datatools/manager/models/FeedSource.java

Lines 284 to 287 in 56f7642

	NotifyUsersForSubscriptionJob.createNotification(
	"feed-updated",
	this.id,
	String.format("New feed version created for %s.", this.name));

One justification for only notifying on fetch is that the fetch could happen overnight in a daily auto-fetch and users would obviously want to know about the new version in this context. Other version creation methods are a bit more manual, so there is less concern about notifying users about something they may have initiated. On the other hand, we make these same notifications in other contexts (e.g., project updated) and there are often more than one user that may find the information about a new version helpful. So I think it is appropriate to expand this notification to other version creation methods as well.