bump version; update news

Author: cpsievert

DESCRIPTION

@@ -1,6 +1,6 @@
 Package: plotly
 Title: Create Interactive Web Graphics via 'plotly.js'
-Version: 3.5.7
+Version: 3.6.0
 Authors@R: c(person("Carson", "Sievert", role = c("aut", "cre"),
     email = "[email protected]"),
     person("Chris", "Parmer", role = c("aut", "cph"),

NEWS

@@ -1,3 +1,20 @@
+3.6.0 -- 16 May 2016
+
+NEW FEATURES & CHANGES:
+
+* Many improvements to the subplot() function:
+  * ggplot2 objects are now officially supported (#520).
+  * Several new arguments allow one to synchronize x/y axes (#298), height/width (#376), hide/show x/y axis titles.
+  * A list of plots can now be passed to the first argument.
+  * A new vignette with examples and more explanation can be accessed via `vignette("subplot")`.
+
+* ggplotly() is now a generic function with a method for ggmatrix objects.
+* plotly_build() is now a generic function. 
+
+BUG FIX: 
+
+Column facet strips will no longer be drawn when there is only one column.
+
 3.5.7 -- 13 May 2016
 
 CHANGES: