Address pytest warnings (#3629)

* Address `boto` deprecation warnings

This commit eliminates the following warning:

../boto/ec2/connection.py:582:
  PendingDeprecationWarning: The current get_all_instances implementation will be replaced with get_all_reservations.

`boto` isn't likely to ever make good on this warning, but doing the replacement will
declutter the `moto` test output.

* Remove `invoke_lambda` tracebacks from unit test logging

If an exception is encountered, the details are returned in the response payload.
Printing the traceback was just adding noise to the pytest output.

* Use known AMIs in unit tests

This commit eliminates the following warning in the pytest output:

`PendingDeprecationWarning: Could not find AMI with image-id:ami-123456, in the near future this will cause an error.`

Known, pre-loaded AMI image ids are used instead of random ids that don't actually
exist in the moto backend.  The integrity of the tests is unaffected by this change.

A test has been added to provide explicit coverage of the PendingDeprecationWarning
raised when an invalid AMI image id is passed to moto.

tests/test_core/test_decorator_calls.py

@@ -21,38 +21,38 @@ def test_basic_connect():
 @mock_ec2_deprecated
 def test_basic_decorator():
     conn = boto.connect_ec2("the_key", "the_secret")
-    list(conn.get_all_instances()).should.equal([])
+    list(conn.get_all_reservations()).should.equal([])
 
 
 @pytest.mark.network
 def test_context_manager():
     conn = boto.connect_ec2("the_key", "the_secret")
     with pytest.raises(EC2ResponseError):
-        conn.get_all_instances()
+        conn.get_all_reservations()
 
     with mock_ec2_deprecated():
         conn = boto.connect_ec2("the_key", "the_secret")
-        list(conn.get_all_instances()).should.equal([])
+        list(conn.get_all_reservations()).should.equal([])
 
     with pytest.raises(EC2ResponseError):
         conn = boto.connect_ec2("the_key", "the_secret")
-        conn.get_all_instances()
+        conn.get_all_reservations()
 
 
 @pytest.mark.network
 def test_decorator_start_and_stop():
     conn = boto.connect_ec2("the_key", "the_secret")
     with pytest.raises(EC2ResponseError):
-        conn.get_all_instances()
+        conn.get_all_reservations()
 
     mock = mock_ec2_deprecated()
     mock.start()
     conn = boto.connect_ec2("the_key", "the_secret")
-    list(conn.get_all_instances()).should.equal([])
+    list(conn.get_all_reservations()).should.equal([])
     mock.stop()
 
     with pytest.raises(EC2ResponseError):
-        conn.get_all_instances()
+        conn.get_all_reservations()
 
 
 @mock_ec2_deprecated
@@ -69,11 +69,11 @@ def test_decorater_wrapped_gets_set():
 class Tester(object):
     def test_the_class(self):
         conn = boto.connect_ec2()
-        list(conn.get_all_instances()).should.have.length_of(0)
+        list(conn.get_all_reservations()).should.have.length_of(0)
 
     def test_still_the_same(self):
         conn = boto.connect_ec2()
-        list(conn.get_all_instances()).should.have.length_of(0)
+        list(conn.get_all_reservations()).should.have.length_of(0)
 
 
 @mock_s3_deprecated

tests/test_core/test_nested.py

@@ -6,6 +6,7 @@ from boto.sqs.message import Message
 from boto.ec2 import EC2Connection
 
 from moto import mock_sqs_deprecated, mock_ec2_deprecated
+from tests import EXAMPLE_AMI_ID
 
 
 class TestNestedDecorators(unittest.TestCase):
@@ -25,4 +26,4 @@ class TestNestedDecorators(unittest.TestCase):
         self.setup_sqs_queue()
 
         conn = EC2Connection()
-        conn.run_instances("ami-123456")
+        conn.run_instances(EXAMPLE_AMI_ID)