Add unit-test to check if interface MIB includes IB and Rec ports

[SuvarnaMeenakshi]

Description

Steps to reproduce the issue:
#244 adds Recirc port support.
Basic unit test is added in the PR. This issue is created to ensure that unit test similar to https://github.com/Azure/sonic-snmpagent/blob/master/tests/namespace/test_interfaces.py#L243 is added for Ethernet-IB and Rec ports.

Describe the results you received:

Describe the results you expected:

Additional information you deem important (e.g. issue happens only occasionally):

**Output of `show version`:**

```
(paste your output here)
```

**Attach debug file `sudo generate_dump`:**

```
(paste your output here)
```