updates the version number

Readme.html

@@ -291,6 +291,11 @@ see javassist.Dump.
 
 <h2>Changes</h2>
 
+<p>-version 3.28
+<ul>
+	<li>GitHub Issue #328.
+</ul>
+
 <p>-version 3.27 on March 19, 2020
 <ul>
    <li>GitHub Issue #271 (PR #279), #280 (PR #281), #282, and PR #294.

src/main/META-INF/MANIFEST.MF

@@ -1,5 +1,5 @@
 Specification-Title: Javassist
 Specification-Vendor: Shigeru Chiba, www.javassist.org
-Specification-Version: 3.27.0-GA
+Specification-Version: 3.28.0-GA
 Main-Class: javassist.CtClass
 Automatic-Module-Name: org.javassist

src/main/javassist/CtClass.java

@@ -69,7 +69,7 @@ public abstract class CtClass {
     /**
      * The version number of this release.
      */
-    public static final String version = "3.27.0-GA";
+    public static final String version = "3.28.0-GA";
 
     /**
      * Prints the version number and the copyright notice.