SP-974 Bump version

Author: bobbrodie

src/bitpay/config.py

@@ -5,6 +5,6 @@ class Config(Enum):
     TEST_URL = "https://test.bitpay.com/"
     PROD_URL = "https://bitpay.com/"
     BITPAY_API_VERSION = "2.0.0"
-    BITPAY_PLUGIN_INFO = "BitPay_Python_Client_v6.0.3"
+    BITPAY_PLUGIN_INFO = "BitPay_Python_Client_v6.0.4"
     BITPAY_API_FRAME = "std"
     BITPAY_API_FRAME_VERSION = "1.0.0"