fix: add function to check the versions after semver

Add a function to check the two versions after the semver specification. Added some unit tests for testing the function too.

(Should fix GH-1, but wasn't fully tested yet)

tests.py

@@ -0,0 +1,19 @@
+import functions
+import unittest
+
+class Tests(unittest.TestCase):
+
+    def checkSimpleVersion(self):
+        self.assertTrue(functions.checkVersion('1.9.1', '1.9.0'))
+
+    def checkTwoIntVersion(self):
+        self.assertTrue(functions.checkVersion('1.10.0', '1.9.0'))
+
+    def checkFalseVersion(self):
+        self.assertFalse(functions.checkVersion('1.8.0', '1.9.0'))
+
+    def checkSameVersion(self):
+        self.assertFalse(functions.checkVersion('1.9.7', '1.9.7'))
+
+if __name__ == '__main__':
+    unittest.main()