You do not need to use moment-timezone for this. The main moment.js library has full functionality for working with UTC and the local time zone.
var testDateUtc = moment.utc("2015-01-30 10:00:00");
var localDate = moment(testDateUtc).local();
From there you can use any of the functions you might expect:
var s = localDate.format("YYYY-MM-DD HH:mm:ss");
var d = localDate.toDate();
// etc...
Note that by passing testDateUtc, which is a moment object, back into the moment() constructor, it creates a clone. Otherwise, when you called .local(), it would also change the testDateUtc value, instead of just the localDate value. Moments are mutable.
Also note that if your original input contains a time zone offset such as +00:00 or Z, then you can just parse it directly with moment. You don't need to use .utc or .local. For example:
var localDate = moment("2015-01-30T10:00:00Z");