Rename "sat/vkB" to "sat/kvB"

It's kilo virtual bytes, not virtual kilobytes.

docs/fidelity-bonds.md

@@ -338,10 +338,10 @@ mixdepth except one.
 
     $ python3 sendpayment.py -N 0 testfidelity3.jmdat 0 BURN
     User data location: .
-    2020-04-07 20:45:25,658 [INFO]  Using this min relay fee as tx fee floor: 1000 sat/vkB (1.0 sat/vB)
+    2020-04-07 20:45:25,658 [INFO]  Using this min relay fee as tx fee floor: 1000 sat/kvB (1.0 sat/vB)
     Enter wallet decryption passphrase: 
     2020-04-07 20:46:50,449 [INFO]  Estimated miner/tx fees for this coinjoin amount: 0.0%
-    2020-04-07 20:46:50,452 [INFO]  Using this min relay fee as tx fee floor: 1000 sat/vkB (1.0 sat/vB)
+    2020-04-07 20:46:50,452 [INFO]  Using this min relay fee as tx fee floor: 1000 sat/kvB (1.0 sat/vB)
     2020-04-07 20:46:50,452 [INFO]  Using a fee of : 0.00000200 BTC (200 sat).
     2020-04-07 20:46:50,454 [INFO]  Got signed transaction:
 

jmbitcoin/jmbitcoin/amount.py

@@ -61,5 +61,5 @@ def sat_to_str_p(sat: int) -> str:
 
 
 def fee_per_kb_to_str(feerate: Any) -> str:
-    return (str(int(feerate)) + " sat/vkB (" +
+    return (str(int(feerate)) + " sat/kvB (" +
         '%.1f' % (int(feerate / 100) / 10) + " sat/vB)")

jmbitcoin/test/test_amounts.py

@@ -111,6 +111,6 @@ def test_sat_to_str_p() -> None:
 
 
 def test_fee_per_kb_to_str() -> None:
-    assert(btc.fee_per_kb_to_str(1000) == "1000 sat/vkB (1.0 sat/vB)")
-    assert(btc.fee_per_kb_to_str(1234) == "1234 sat/vkB (1.2 sat/vB)")
-    assert(btc.fee_per_kb_to_str(1999) == "1999 sat/vkB (1.9 sat/vB)")
+    assert(btc.fee_per_kb_to_str(1000) == "1000 sat/kvB (1.0 sat/vB)")
+    assert(btc.fee_per_kb_to_str(1234) == "1234 sat/kvB (1.2 sat/vB)")
+    assert(btc.fee_per_kb_to_str(1999) == "1999 sat/kvB (1.9 sat/vB)")