upgrade flask-bcrypt to 0.7.1

this uses bcrypt directly rather than using the wrapper python-bcrypt.
WARNING! You'll need to update your local install by running:

```
pip uninstall python-bcrypt
pip install flask-bcrypt==0.7.1
```

app/encryption.py

@@ -16,7 +16,7 @@ class Encryption:
 
 
 def hashpw(password):
-    return generate_password_hash(password.encode('UTF-8'), 10)
+    return generate_password_hash(password.encode('UTF-8'), 10).decode('utf-8')
 
 
 def check_hash(password, hashed_password):