fix unit tests, add more nodes

beem/utils.py

@@ -234,9 +234,10 @@ def make_patch(a, b, n=3):
 def get_node_list(appbase=False):
     """Returns node list"""
     if appbase:
-        return ["https://api.steem.house", "https://api.steemit.com", "wss://appbasetest.timcliff.com"]
+        return ["https://api.steem.house", "https://api.steemit.com", "wss://steemd.steemitstage.com", 
+                "wss://steemd.steemitdev.com", "wss://appbasetest.timcliff.com"]
     else:
-        return ["wss://rpc.buildteam.io", "wss://steemd.pevo.science", "wss://gtg.steem.house:8090", "wss://rpc.steemliberator.com",
+        return ["wss://steemd.privex.io", "wss://steemd.pevo.science", "wss://rpc.steemliberator.com", "wss://rpc.buildteam.io", "wss://gtg.steem.house:8090", 
                 "wss://rpc.steemviz.com", "wss://seed.bitcoiner.me", "wss://steemd.steemgigs.org",
                 "wss://steemd.minnowsupportproject.org", "https://rpc.buildteam.io",
                 "https://steemd.minnowsupportproject.org", "https://steemd.pevo.science", "https://rpc.steemviz.com", "https://seed.bitcoiner.me",

tests/beem/test_txbuffers.py

@@ -17,10 +17,9 @@ from beem.exceptions import (
     InvalidWifError,
     WalletLocked
 )
-from beemgraphenebase.transactions import formatTimeFromNow
 from beemapi import exceptions
 from beem.wallet import Wallet
-from beem.utils import get_node_list
+from beem.utils import get_node_list, formatTimeFromNow
 
 wif = "5KQwrPbwdL6PhXujxW37FSSQZ1JiwsST4cqQzDeyXtP79zkvFD3"