Begin making 3.0 adjustments

Author: jasmith-hs

3.0-changes.md

@@ -0,0 +1,3 @@
+- Migrated JinjavaConfig to immutable
+- Removed whitespaceRequiredWithinTokens LegacyOverride and converted to BuiltinFeatures
+- 

README.md

@@ -78,7 +78,7 @@ You will likely want to provide your own implementation of
 `ResourceLoader` to hook into your application's template repository, and then tell jinjava about it:
 
 ```java
-JinjavaConfig config = new JinjavaConfig();
+JinjavaConfig config = JinjavaConfig.builder().build();
 
 Jinjava jinjava = new Jinjava(config);
 jinjava.setResourceLocator(new MyCustomResourceLocator());
@@ -87,7 +87,7 @@ jinjava.setResourceLocator(new MyCustomResourceLocator());
 To use more than one `ResourceLocator`, use a `CascadingResourceLocator`. 
 
 ```java
-JinjavaConfig config = new JinjavaConfig();
+JinjavaConfig config = JinjavaConfig.builder().build();
 
 Jinjava jinjava = new Jinjava(config);
 jinjava.setResourceLocator(new MyCustomResourceLocator(), new FileResourceLocator());

pom.xml

@@ -10,7 +10,7 @@
 
   <groupId>com.hubspot.jinjava</groupId>
   <artifactId>jinjava</artifactId>
-  <version>2.8.3-SNAPSHOT</version>
+  <version>3.0.0-SNAPSHOT</version>
 
   <name>${project.groupId}:${project.artifactId}</name>
   <description>Jinja templating engine implemented in Java</description>

src/main/java/com/hubspot/jinjava/Jinjava.java

@@ -73,7 +73,7 @@ public class Jinjava {
    * Create a new Jinjava processor instance with the default global config
    */
   public Jinjava() {
-    this(new JinjavaConfig());
+    this(JinjavaConfig.newBuilder().build());
   }
 
   /**