463/hotfix/exception on aws network error

[ShayNehmad]

Feature / Fixes

Fixes #463 .

• Have you added an explanation of what your changes do and why you'd like to include them?

• Have you successfully tested your changes locally?

• Example screenshot/log transcript of the feature working
  I've added the line raise Exception('F') to the AwsInstance class to simulate an unknown error.

2019-10-13 11:05:14,516 - environment.py:46 -   <module>() - INFO - Monkey's env is: StandardEnvironment
2019-10-13 11:05:15,276 - report_generation_synchronisation.py:9 -   <module>() - DEBUG - Initializing report generation locks.
2019-10-13 11:05:16,380 - main.py:85 - assert_mongo_db_version() - INFO - Mongo DB version OK. Got (u'4', u'1', u'0-158-g3d62f3cd37')
2019-10-13 11:05:23,743 - remote_run_aws.py:38 - try_init_aws_instance() - ERROR - Failed init aws instance. Exception info: 
Traceback (most recent call last):
  File "C:\Users\shay.nehmad\PycharmProjects\monkey\monkey\monkey_island\cc\services\remote_run_aws.py", line 36, in try_init_aws_instance
    RemoteRunAwsService.aws_instance = AwsInstance()
  File "C:\Users\shay.nehmad\PycharmProjects\monkey\monkey\common\cloud\aws_instance.py", line 23, in __init__
    raise Exception("F")
Exception: F
2019-10-13 11:05:36,701 - exporter_init.py:26 - try_add_aws_exporter_to_manager() - ERROR - Failed adding aws exporter to manager. Exception info:
Traceback (most recent call last):
  File "C:\Users\shay.nehmad\PycharmProjects\monkey\monkey\monkey_island\cc\services\reporting\exporter_init.py", line 23, in try_add_aws_exporter_to_manager
    if RemoteRunAwsService.is_running_on_aws() and ('aws' == env.get_deployment()):
  File "C:\Users\shay.nehmad\PycharmProjects\monkey\monkey\monkey_island\cc\services\remote_run_aws.py", line 58, in is_running_on_aws
    return RemoteRunAwsService.aws_instance.is_aws_instance()
AttributeError: 'NoneType' object has no attribute 'is_aws_instance'
2019-10-13 11:06:02,450 - remote_run_aws.py:38 - try_init_aws_instance() - ERROR - Failed init aws instance. Exception info: 
Traceback (most recent call last):
  File "C:\Users\shay.nehmad\PycharmProjects\monkey\monkey\monkey_island\cc\services\remote_run_aws.py", line 36, in try_init_aws_instance
    RemoteRunAwsService.aws_instance = AwsInstance()
  File "C:\Users\shay.nehmad\PycharmProjects\monkey\monkey\common\cloud\aws_instance.py", line 23, in __init__
    raise Exception("F")
Exception: F
2019-10-13 11:06:08,950 - main.py:60 - log_init_info() - INFO - Monkey Island Server is running. Listening on the following URLs: https://10.28.0.111:5000, https://10.0.0.212:5000, https://172.17.218.17:5000
[...]

Changes

• Added exception suppression to all usages of AwsInstance except places where specifically not required (which were documented).