Docs: use gender neutral language

Author: michaelsproul

README.md

@@ -69,7 +69,7 @@ If you have never created an account before press "Create New Account". Provide
 
 If you already have an account just write the name and the password here.
 
-All accounts are created in the rotkehlchen directory which is located in: `$HOME/.rotkehlchen`. Each user has his own subdirectory.
+All accounts are created in the rotkehlchen directory which is located in: `$HOME/.rotkehlchen`. Each user has their own subdirectory.
 
 ### Changing the Profit Currency
 

rotkehlchen/data_handler.py

@@ -130,7 +130,7 @@ def unlock(self, username: str, password: str, create_new: bool) -> typing.FileP
             if not os.path.exists(os.path.join(user_data_dir, 'rotkehlchen.db')):
                 # This is bad. User directory exists but database is missing.
                 # Make a backup of the directory that user should probably remove
-                # on his own. At the same time delete the directory so that a new
+                # on their own. At the same time delete the directory so that a new
                 # user account can be created
                 shutil.move(
                     user_data_dir,