Improved download page

- mention that Juno currently contains JGit 2.1 only since 2.2 was
released after Juno SR1
- mention that JGit is available on Maven central

Change-Id: I11afa6851a2a12e254f2714eeb9f9ba1b5e0db1f
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
1 file changed