added missing phonemes, synthesizer.py now setup the correct input layer

tests/symbols_tests.py

@@ -0,0 +1,7 @@
+import unittest
+
+from utils.text import phonemes
+
+class SymbolsTest(unittest.TestCase):
+    def test_uniqueness(self):
+        assert sorted(phonemes) == sorted(list(set(phonemes)))