revisit artificially restricting zoom of tiled basemaps

[jgravois]

we currently set the maximum zoom level of our gray basemaps at 16, but these basemaps were updated with additional zoom levels to match the others a long time ago.

http://services.arcgisonline.com/arcgis/rest/services/Canvas/World_Light_Gray_Base/MapServer

for that matter, even the World Topographic basemap lists zoom levels all the way down to 23 now!

[jgravois]

this would be a really straightforward fix if anyone is looking for an excuse to make their first foray into open source 😉 😉

[jgravois]

steps to reproduce:

1. launch our Switching basemaps sample
2. zoom in 6 times
3. choose 'Gray' from the basemap toggle and notice that its not possible to zoom in farther.

same rules apply as #647

[machikoyasuda]

adding this issue to the next Fullstack meetup for people to dig into :) fullstackla/pairing-meetup#161

[jgravois]

turns out the current behavior is as designed.

for the curious, more info can be found in #981