[enh] README.md: new testing currency, update links, center images.

- New testing currency
- Update links
- Center images

README.md

-![Duniter logo](https://raw.github.com/duniter/duniter/master/duniter-logos/250×250.png)
+<p align="center"><img src="https://raw.github.com/duniter/duniter/master/duniter-logos/duniter-logo.svg" width="250" height="250"></p>
 
 # Duniter [![Build Status](https://api.travis-ci.org/duniter/duniter.png)](https://travis-ci.org/duniter/duniter) [![Coverage Status](https://coveralls.io/repos/duniter/duniter/badge.svg?branch=master&service=github)](https://coveralls.io/github/duniter/duniter?branch=master)
 
 Duniter (previously uCoin) is a libre software allowing to create a new kind of P2P crypto-currencies based on individuals and Universal Dividend.
 
-Inspired by [Bitcoin](https://github.com/bitcoin/bitcoin) and [OpenUDC project](https://github.com/Open-UDC/open-udc).
+Inspired by [Bitcoin](https://github.com/bitcoin/bitcoin) and [OpenUDC](https://github.com/Open-UDC/open-udc) projects.
 
 ## Development state
 
 Software is still under development, and **no production currency using Duniter exists for now**.
 
-However, it already exists a testing currency named [MetaBrouzouf](http://duniter.org/try/). Want to test it? Two ways.
+However, it already exists a testing currency named [Test_Net](https://forum.duniter.org/t/join-our-new-testnet-currency/813). Want to test it? Two ways.
 
 ### Add your node to the network
 
 ```
 $ wget -qO- https://raw.githubusercontent.com/duniter/duniter/master/install.sh | bash
 $ duniter init
-$ duniter sync metab.ucoin.io 9201
+$ duniter sync duniter.org 8999
 $ duniter start
 ```
 
-and you are done! See [Install documentation](https://github.com/duniter/duniter/wiki/Install-uCoin-node) for further details.
+and you are done! See [Install documentation](https://github.com/duniter/duniter/wiki/Install-Duniter-node) for further details.
 
 ### Try Sakia Wallet
 
-In the world of crypto-currencies, [Sakia Wallet](http://sakia-wallet.org/) would be called a [SPV](https://en.bitcoin.it/wiki/Thin_Client_Security#Simplified_Payment_Verification_.28SPV.29_Clients) client. It is a graphical client connecting to the network. See this [tutorial](https://forum.duniter.org/t/subscribing-to-meta-brouzouf-testing-currency/199) to join in the testing currency with Sakia.
+In the world of crypto-currencies, [Sakia Wallet](http://sakia-wallet.org/) would be called a [SPV](https://en.bitcoin.it/wiki/Thin_Client_Security#Simplified_Payment_Verification_.28SPV.29_Clients) client. It is a graphical client connecting to the network. See this [tutorial](https://forum.duniter.org/t/join-our-new-testnet-currency/813) to join in the testing currency with Sakia.
 
-![Sakia screenshot](http://sakia-wallet.org/img/Dividends.png)
+<p align="center"><img src="http://sakia-wallet.org/img/Dividends.png"></p>
 
 ## Going further
 
 ### Documentation
 
-Visit [Duniter website](http://duniter.org): it gathers theoretical informations, FAQ and several useful links. If you want to learn, this is the first place to visit.
+Visit [Duniter website](https://duniter.org): it gathers theoretical informations, FAQ and several useful links. If you want to learn, this is the first place to visit.
 
 ### Talk about/get involved in Duniter project
 
@@ -47,8 +47,8 @@ If you wish to participate/debate on Duniter, you can:
 # References
 
 ## Theoretical
-* [[en] Relative theory of money](http://vit.free.fr/TRM/en_US/)
-* [[fr] Théorie relative de la monaie](http://trm.creationmonetaire.info/)
+* [[en] Relative theory of money](http://en.trm.creationmonetaire.info)
+* [[fr] Théorie relative de la monaie](http://trm.creationmonetaire.info)
 
 ## OpenUDC