Fix mypy issues, prepare for release

pydriller/domain/commit.py

@@ -235,7 +235,7 @@ def language_supported(self) -> bool:
         return lizard_languages.get_reader_for(self.filename) is not None
 
     @property
-    def nloc(self) -> int:
+    def nloc(self) -> Optional[int]:
         """
         Calculate the LOC of the file.
 
@@ -245,7 +245,7 @@ def nloc(self) -> int:
         return self._nloc
 
     @property
-    def complexity(self) -> int:
+    def complexity(self) -> Optional[int]:
         """
         Calculate the Cyclomatic Complexity of the file.
 
@@ -255,7 +255,7 @@ def complexity(self) -> int:
         return self._complexity
 
     @property
-    def token_count(self) -> int:
+    def token_count(self) -> Optional[int]:
         """
         Calculate the token count of functions.
 

setup.py

@@ -20,7 +20,7 @@
     long_description=long_description,
     author='Davide Spadini',
     author_email='[email protected]',
-    version='1.14',
+    version='1.15',
     packages=find_packages('.'),
     url='https://github.com/ishepard/pydriller',
     license='Apache License',