Protected Client Properties

[drmmr763]

Hi @jonathanraftery

This PR makes the properties class protected instead of private.

Reasoning:

• The Bullhorn session auth process is very slow (a few seconds)
• To resolve this I wish to create a maintained session and refresh every few minutes to ensure my application always has an authenticated session
• The Client class's design only allows populates the $httpClient object after the initiateSession method (or similar refresh methods) is explicitly called.
• I want to extend / override the Client class and modify this behavior to set the httpClient property in the constructor and utilize the data store to get / retrieve stored session data. This way it will always have a populated httpClient object.
• The the private properties block from (easily) doing this.

Let me know if you think this logic / approach makes sense.

[jonathanraftery]

Makes sense. No reason to prevent derivation by keeping these members private.

Merged. Thanks!