test_lightning.py: fix float insanity with values.

When is 0.01 != 0.01?  When there are floats involved!  Jenkins hit an
error once, I have no idea why.

This works around the following intermittant error:

ERROR: test_closing_negotiation_reconnect (__main__.LightningDTests)
----------------------------------------------------------------------
Traceback (most recent call last):
File "tests/test_lightningd.py", line 1601, in test_closing_negotiation_reconnect
self.fund_channel(l1, l2, 10**6)
File "tests/test_lightningd.py", line 241, in fund_channel
raise ValueError("Can't find {} payment in {}".format(amount, tx))
ValueError: Can't find 1000000 payment in 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

For testing, that tx decodes to:
{
  "txid": "0165e92be762b352b665b76b9872d5189e1b2a8faf4918ab3cca7cd5d4b6a5fa",
  "hash": "8af9a36c79ee5243468c5cbed1c80f10238fba405f0ad957a0c2cfc46fb632f5",
  "version": 2,
  "size": 257,
  "vsize": 176,
  "locktime": 0,
  "vin": [
    {
      "txid": "26c00a67045b5bc585c3f2cd9ae5c0447baee163c297f159eefa1629e97bb2b0",
      "vout": 1,
      "scriptSig": {
        "asm": "001401fad90abcd66697e2592164722de4a95ebee165",
        "hex": "16001401fad90abcd66697e2592164722de4a95ebee165"
      },
      "txinwitness": [
        "3044022017bd19a0ee85532f67a280c71ed02d1321f08975334bd281527478022265225702202ec448bf9c0890a31a26f0ef4f03d298c8ec16b277faff09a70ddd335df44b6e01",
        "03d745445c9362665f22e0d96e9e766f273f3260dea39c8a76bfa05dd2684ddccf"
      ],
      "sequence": 4294967295
    }
  ],
  "vout": [
    {
      "value": 0.00990565,
      "n": 0,
      "scriptPubKey": {
        "asm": "0 c2ccab171c2a5be9dab52ec41b825863024c5466",
        "hex": "0014c2ccab171c2a5be9dab52ec41b825863024c5466",
        "type": "witness_v0_keyhash"
      }
    },
    {
      "value": 0.01000000,
      "n": 1,
      "scriptPubKey": {
        "asm": "0 5b8cd3b914cf67cdd8fa6273c930353dd36476734fbd962102c2df53b90880cd",
        "hex": "00205b8cd3b914cf67cdd8fa6273c930353dd36476734fbd962102c2df53b90880cd",
        "type": "witness_v0_scripthash"
      }
    }
  ]
}

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

tests/test_lightningd.py

@@ -236,8 +236,10 @@ class LightningDTests(BaseLightningDTests):
 
         # Hacky way to find our output.
         for out in bitcoind.rpc.decoderawtransaction(tx)['vout']:
-            if out['scriptPubKey']['type'] == 'witness_v0_scripthash' and out['value'] == Decimal(amount) / 10**8:
-                return "{}:1:{}".format(bitcoind.rpc.getblockcount(), out['n'])
+            # Sometimes a float?  Sometimes a decimal?  WTF Python?!
+            if out['scriptPubKey']['type'] == 'witness_v0_scripthash':
+                if out['value'] == Decimal(amount) / 10**8 or out['value'] * 10**8 == amount:
+                    return "{}:1:{}".format(bitcoind.rpc.getblockcount(), out['n'])
         raise ValueError("Can't find {} payment in {}".format(amount, tx))
 
     def pay(self, lsrc, ldst, amt, label=None, async=False):