Update README.md

- set version in POM snippet from 1.0.2 to 1.2.3
- set URL to Ant Task docs to http://jeremylong.github.io/DependencyCheck/dependency-check-ant/installation.html
Merge branch 'patch-1' of github.com:bkimminich/DependencyCheck into bkimminich-patch-1
Merge branch 'bkimminich-patch-1'