Update Moment.js from 2.8.3 to 2.8.4

Update Moment.js from 2.8.3 to 2.8.4

Project site
* http://momentjs.com
* https://github.com/moment/moment/

File source
* https://github.com/moment/moment/tree/2.8.4

Changelog
* https://github.com/moment/moment/blob/2.8.4/CHANGELOG.md

Difference between 2.8.3 and 2.8.4

2.8.4

Features

* #2000 Add LTS localised format that includes seconds
* #1960 added formatToken 'x' for unix offset in milliseconds #1938
* #1965 Support 24:00:00.000 to mean next day, at midnight.
* #2002 Accept 'date' key when creating moment with object
* #2009 Use native toISOString when we can

Bugfixes

* #2004 Fix makeAs to work with zoned moments
* #2001 moment.utc(string) falling back to Date works properly
* #1928 IE11 module == null
* #1952 New implementation of isBefore/isSame/isAfter
* #1992 Fix strict month parsing of abbreviated/full months
* #2003 Detect hours above 12 with h/hh tokens
* #1974 Locale export for meteor server environment
* #1925 Fix duration as getters (years and months convert to whole days)
* #2008 Fix endOf handling of no-arg and ms
* #2010 Update deprecation warning for moment().lang()

Locale improvements

* #2015 remove Uhr from german format
* #1933 improved russian lastWeek translations
* #2013 changed month abbreviations in russian
* #1971 Fix italian calendar time
* #1967 Fix catalan ordinals
* #1898 Bosnian translation of August
* #1771 Update greek seconds string
* #1961 Add a script to prepare moment for npm publish
* #2016 Fix long date format for Czech

Change-Id: I136a08194476ac01af7495c8f8e1e7ea1e140973