Update README.md

Author: Simon Pearce

README.md

@@ -7,9 +7,9 @@ Mathematical details on the Compound Matrix Method may be found <a href=http://w
  The initial version is available as a  `.paclet` file. Download and install it using the `PacletInstall` function in Mathematica:  
 
         Needs["PacletManager`"]
-        PacletInstall["https://github.com/SPPearce/CompoundMatrixMethod/releases/download/v0.3/CompoundMatrixMethod-0.3.paclet"]
+        PacletInstall["https://github.com/SPPearce/CompoundMatrixMethod/releases/download/v0.4/CompoundMatrixMethod-0.4.paclet"]
         
- Alternatively, download the paclet locally and install using `PacletInstall` on the appropriate directory. For example, if the file was downloaded to the directory `~/Downloads`, evaluate  `PacletInstall["~/Downloads/CompoundMatrixMethod-0.3.paclet"]`
+ Alternatively, download the paclet locally and install using `PacletInstall` on the appropriate directory. For example, if the file was downloaded to the directory `~/Downloads`, evaluate  `PacletInstall["~/Downloads/CompoundMatrixMethod-0.4.paclet"]`
 
 The package can then be loaded by calling