ENH: Allow passing of flags in replace

Author: jseabold

pandas/core/strings.py

@@ -692,8 +692,9 @@ def contains(self, pat, case=True, flags=0, na=np.nan):
         return self._wrap_result(result)
 
     @copy(str_replace)
-    def replace(self, pat, repl, n=-1, case=True):
-        result = str_replace(self.series, pat, repl, n=n, case=case)
+    def replace(self, pat, repl, n=-1, case=True, flags=0):
+        result = str_replace(self.series, pat, repl, n=n, case=case,
+                             flags=flags)
         return self._wrap_result(result)
 
     @copy(str_repeat)