Fixed some issues

src/main/java/ch/dissem/msgpack/types/MPFloat.java

@@ -63,6 +63,8 @@ public class MPFloat implements MPType<Double> {
                 out.write(0xCB);
                 out.write(ByteBuffer.allocate(8).putDouble(value).array());
                 break;
+            default:
+                throw new IllegalArgumentException("Unknown precision: " + precision);
         }
     }
 

src/main/java/ch/dissem/msgpack/types/MPString.java

@@ -43,6 +43,8 @@ public class MPString implements MPType<String>, CharSequence {
 
     private static Charset encoding = Charset.forName("UTF-8");
 
+    private final String value;
+
     /**
      * Use this method if for some messed up reason you really need to use something else than UTF-8.
      * Ask yourself: why should I? Is this really necessary?
@@ -55,8 +57,6 @@ public class MPString implements MPType<String>, CharSequence {
         MPString.encoding = encoding;
     }
 
-    private final String value;
-
     public MPString(String value) {
         this.value = value;
     }