Updated Event Page
Updated Event Page

updated language to remove outdated text like "upcoming" for 2017. Also
removed Giveaway numbers in section titles. Added Esri Dev Summit 2018
buttons in nav bar and top section, linked up the nav to these as
"event4"

TheSpatialCommunity/TheSpatialCommunity.github.io,TheSpatialCommunity/TheSpatialCommunity.github.io,TheSpatialCommunity/TheSpatialCommunity.github.io