Hardcode node keypair for testing purposes

and remove the configure command since env vars are sufficient

travis-before-script.sh

@@ -4,7 +4,8 @@ set -e -x
 
 if [ "${TOXENV}" == "py35" ]; then
     rethinkdb --daemon
-    bigchaindb -y configure rethinkdb
+    export BIGCHAINDB_KEYPAIR_PUBLIC=GW1nrdZm4mbVC8ePeiGWz6DqHexqewqy5teURVHi3RG4
+    export BIGCHAINDB_KEYPAIR_PRIVATE=2kQgBtQnHoauw8QchKM7xYvEBW1QDoHzhBsCL9Vi1AzB 
 
     # Start BigchainDB in the background and ignore any output
     bigchaindb start >/dev/null 2>&1 &