Merge pull request #484 from crytic/dev-slither-simil-pickle

Fixed numpy error while running slither-simil test command

slither/tools/similarity/cache.py

@@ -9,7 +9,7 @@ except ImportError:
 
 def load_cache(infile, nsamples=None):
     cache = dict()
-    with np.load(infile) as data:
+    with np.load(infile, allow_pickle=True) as data:
         array = data['arr_0'][0]
         for i,(x,y) in enumerate(array):
             cache[x] = y