Add .perlcritic policy overrides for test suite

.perlcritic

@@ -0,0 +1,17 @@
+# Perl::Critic policy overrides for the testssl.sh test suite (t/)
+#
+# see https://github.com/Perl-Critic/Perl-Critic
+
+# General setting: That would deliver way more
+# severity = 3
+
+
+# Test helpers commonly use subroutine prototypes (e.g. sub helper ($$));
+# harmless in test code.
+[Subroutines::ProhibitSubroutinePrototypes]
+severity = 4
+
+# Intentional octal file-permission literals (0400, 0100) in t/00_testssl_help.t.
+[ValuesAndExpressions::ProhibitLeadingZeros]
+severity = 4
+