[MIT-3253] Create Http interface for executing API request

[rosle]

Description

• Create Http interface for API request
• Reorganize unit test files in the project

More information

To make it easier to implement tests for API request, I did a quick update by extracting the executeCurl and executeTest to a new class with a new interface - OmiseHttpExecutorInterface. The logic for both functions remain unchanged.

API Mock Example

with Mockery:

$omiseHttpExecutorMock = Mockery::mock('overload:' . OmiseHttpExecutor::class);
$omiseHttpExecutorMock
  ->shouldReceive('execute')
  ->once()
  ->andReturn('<API Response>');

Also, I update the unit test directory by moving all tests inside unit folder:

Related links:

• https://opn-ooo.atlassian.net/browse/MIT-3175

Rollback procedure

default rollback procedure