Add Testing

[maxholloway]

Add Testing

Motivation

There's basically no unit testing happening! Huge issue!! Unacceptable!!!

Solution

1. Do a thorough search into how testing is performed in Julia.
2. Write unit tests, starting from the bottom up, using a Julia standardized testing format. This entails writing tests for the sub-modules in the following batches:
      1. Events, DataReaders
      2. Engine
      3. Backtest
      4. Utils

[maxholloway]

/cib

[create-issue-branch]

Branch issue-7-Add_Testing created!

[maxholloway]

Still incomplete! None of the Backtest interface functions are directly tested yet. ☹️