Automatically initialize things (#33)

Author: alexarchambault

almond/src/main/scala/plotly/Almond.scala

@@ -10,6 +10,10 @@ import plotly.layout._
 
 object Almond {
 
+  object Internal {
+    @volatile var initialized = false
+  }
+
   def init(offline: Boolean = false)(implicit publish: OutputHandler): Unit = {
 
     // offline mode like in plotly-python
@@ -77,6 +81,14 @@ object Almond {
     publish: OutputHandler
   ): String = {
 
+    if (!Internal.initialized)
+      Internal.synchronized {
+        if (!Internal.initialized) {
+          init()
+          Internal.initialized = true
+        }
+      }
+
     val div0 =
       if (div.isEmpty)
         randomDiv()