Omspy

Fixes
* Same memory id for `PegExisting` order. See 21
* Negative mtm for trailing algo fixed 49

Breaking Changes
* **Kotak** broker removed. Deprecated code available at [omspy-brokers](https://github.com/uberdeveloper/omspy-brokers)
Features
* New algo for trailing added in `algos/trailing`
* New broker `Noren` added
Improvements
* `FakeBroker` return formats improved. See 42
* All brokers must return orders as empty list if no orders are found (instead of a dictionary inside list or other format)
Fixes
* exch_tm error fixed for `Finvasia` broker 46.
* `ReplicaBroker` not to raise error if instruments not available 41.

Fixes
* average_price for `FakeBroker` would take care of None values in price or trigger_price

Fixes
* 45 Type conversion fixed
* Deprecation message added for inactive broker modules
Improvments
* 41 return order_id only

Features
* STOP order simulation added to `OrderFill` 40
* `utils.load_broker` to automatically load broker from credentials file
Improvements
* finvasia broker upgraded to Norenapi version 0.3
* 38 All brokers to be initialized to None
* 39 All broker connections to be done only during authentication
* extra attribute added to yaml files for all brokers
* `pytop` library added to main dependency

Fixes
* `orders` property for all brokers to return empty list in case of errors (no empty dictionary inside list)
* **Neo** broker `orders` property to infer side automatically
* **Icici** broker proper data conversion for orders
* 35 when both random numbers are same, the end number is changed automatically to prevent raising error

Fixes
* side added to `orders` property in `Neo` broker