Delete .jenkins.sh as it uses a pipeline instead

.jenkins.sh

-#!/bin/bash
-
-specfiles=$(ls | egrep "^[^.]*.(json|yaml)")
-
-fres=0
-for i in $specfiles ; do
-    echo "-- Validating and linting OpenAPI file $i..."
-    swagger-cli validate $i
-    res=$?
-    speccy lint "$i"
-    res2=$?
-    fres=$(($fres||$res||$res2))
-    echo "--- Validator returned $res, linter returned $res2."
-done
-
-echo "-- Final validator returns $fres."
-exit $fres
-