Use pylint 2.8.2

CONTRIBUTING.md

@@ -37,7 +37,7 @@ To run them locally in the root dir of the repository:
 - `pylint slither tests --rcfile pyproject.toml`
 - `black . --config pyproject.toml`
 
-We use pylint `2.7.2` black `20.8b1`.
+We use pylint `2.8.2` black `20.8b1`.
 ### Detectors tests
 
 For each new detector, at least one regression tests must be present.

slither/tools/upgradeability/checks/constant.py

@@ -48,8 +48,7 @@ Do not remove `constant` from a state variables during an update.
         state_variables_v2 = contract_v2.state_variables
 
         v2_additional_variables = len(state_variables_v2) - len(state_variables_v1)
-        if v2_additional_variables < 0:
-            v2_additional_variables = 0
+        v2_additional_variables = max(v2_additional_variables, 0)
 
         # We keep two index, because we need to have them out of sync if v2
         # has additional non constant variables
@@ -130,8 +129,7 @@ Do not make an existing state variable `constant`.
         state_variables_v2 = contract_v2.state_variables
 
         v2_additional_variables = len(state_variables_v2) - len(state_variables_v1)
-        if v2_additional_variables < 0:
-            v2_additional_variables = 0
+        v2_additional_variables = max(v2_additional_variables, 0)
 
         # We keep two index, because we need to have them out of sync if v2
         # has additional non constant variables