Added option to disable creating the log group

[guillaumesmo]

• What kind of change does this PR introduce? (Bug fix, feature, docs update, ...)
  feature

• What is the current behavior? (You can also link to an open issue here)
  The handler checks for existence of the given log group, if it doesn't exist, it created the log group

• What is the new behavior (if this is a feature change)?
  By enabling the option, the handler doesn't check for the group's existence and goes on with initializing the stream.

• Does this PR introduce a breaking change? (What changes might users need to make in their application due to this PR?)
  No, existing behavior remains unchanged.
  User has to explicitly trigger the option

• Other information:
  This change was made in an effort to reduce the security boundaries of the application (I create the log group beforehand and don't need the app to have logs:DescribeLogGroups and logs:CreateLogGroup permissions. Also, not checking if the group exists improves the performance by removing the HTTP call.

Please let me know what you think about it.

Alternatively, I propose to make the initialize and refreshSequenceToken methods protected, because currently there's no way to achieve my change by extending the class, so copy-pasting the whole class is the only solution.

[coveralls]

Coverage decreased (-0.5%) to 91.515% when pulling cb6e851 on guillaumesmo:disable-create-group into e9bc1f2 on maxbanton:master.

[coveralls]

Coverage decreased (-0.02%) to 91.975% when pulling 7650896 on guillaumesmo:disable-create-group into e9bc1f2 on maxbanton:master.

[maxbanton]

Hi @guillaumesmo!
Thanks for your PR.
Nice point about reducing security boundaries, I like it.
What about adding your option to the constructor?

Regards,
Max.

[guillaumesmo]

Hello @maxbanton

I was thinking about doing that first but since the constructor already has plenty of arguments I preferred not to

I'll update my branch

[guillaumesmo]

Hi @maxbanton

Any news if this could be merged?

Thank you

[maxbanton]

Hi @guillaumesmo!
You PR is merged now and new version v.1.1.14 is published.

[guillaumesmo]

Thank you, and happy new year ;)