Removing reference to javaslang 2.0.0 vesion which may be confusing for vavr users (#48)

Author: sleepytomcat

src/docs/asciidoc/usage_guide.adoc

@@ -266,7 +266,7 @@ Lazy is a monadic container type which represents a lazy evaluated value. Compar
 include::../../test/java/io/vavr/LazyDemo.java[tags=createLazy]
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-Since version 2.0.0 you may also create a real lazy value (works only with interfaces):
+You may also create a real lazy value (works only with interfaces):
 
 [source,java,indent=0]
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