Merge pull request #516 from faraggi/content/docs-client-reference

fixes #515 : ethereum.org 404 error link is fixed and pantheon client is added

src/docs/truffle/reference/choosing-an-ethereum-client.md

@@ -47,11 +47,12 @@ There are many official and unofficial Ethereum clients available for you to use
 
 * Geth (go-ethereum): [https://github.com/ethereum/go-ethereum](https://github.com/ethereum/go-ethereum)
 * WebThree (cpp-ethereum): [https://github.com/ethereum/cpp-ethereum](https://github.com/ethereum/cpp-ethereum)
+* Pantheon (java): [https://github.com/PegaSysEng/pantheon](https://github.com/PegaSysEng/pantheon)
 * Parity: [https://github.com/paritytech/parity](https://github.com/paritytech/parity)
-* More: [https://www.ethereum.org/cli](https://www.ethereum.org/cli)
+* More: [https://www.ethereum.org/developers/#clients-running-your-own-node](https://www.ethereum.org/developers/#clients-running-your-own-node)
 
 These are full client implementations that include mining, networking, blocks and transaction processing. You should use these clients after you've sufficiently tested your dapp with Ganache or Truffle Develop and you're ready to deploy to your desired Ethereum network.
 
 ## Deploying to private networks
 
-Private networks utilize the same technology as with live networks, but with a different configuration. So you can configure any of the Ethereum clients mentioned above to run a private network, and deploy to it in exactly the same way.
+Private networks utilize the same technology as with live networks, but with a different configuration. So you can configure any of the Ethereum clients mentioned above to run a private network, and deploy to it in exactly the same way.