Merge pull request #799 from crytic/dev-gwei

Add gwei support

slither/utils/arithmetic.py

@@ -2,7 +2,7 @@ from decimal import Decimal
 
 from slither.exceptions import SlitherException
 
-
+# pylint: disable=too-many-branches
 def convert_subdenomination(
     value: str, sub: str
 ) -> int:  # pylint: disable=too-many-return-statements
@@ -14,6 +14,8 @@ def convert_subdenomination(
         decimal_value = Decimal(value)
     if sub == "wei":
         return int(decimal_value)
+    if sub == "gwei":
+        return int(decimal_value * int(1e9))
     if sub == "szabo":
         return int(decimal_value * int(1e12))
     if sub == "finney":