feature - add teardown options to terraform fixture

[marcoceppi]

There's two ways I see to approach this. The first is what's in this PR where TEARDOWN_* is mapped to the right teardown value. The second is to just have a teardown member on the class that's set to pytest_terraform.options.teardown. That would yield:

from pytest_terraform import terraform


@terraform('aws_sqs', teardown=terraform.teardown.IGNORE)
def test_sqs(aws_sqs):
    assert aws_sqs["aws_sqs_queue.test_queue.tags"] == {
        "Environment": "production"
    }
   queue_url = aws_sqs['test_queue.queue_url']
   print(queue_url)

Open to either approach, or even something different, to make developer experience a little cleaner

[codecov]

Codecov Report

Merging #24 into master will increase coverage by 0.04%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master      #24      +/-   ##
==========================================
+ Coverage   92.51%   92.56%   +0.04%     
==========================================
  Files           8        8              
  Lines         454      457       +3     
==========================================
+ Hits          420      423       +3     
  Misses         34       34              

Impacted Files	Coverage Δ
pytest_terraform/tf.py	96.24% <100.00%> (+0.04%)	⬆️

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[kapilt]

ergonomics here favor terraform.TEARDOWN_IGNORE versus nested object usage, imo.

[kapilt]

lgtm