Added nearly all ACM method implementations

Added cryptography>=2.0.0 to install deps
Created base backend and certificate objects
Implemented most of the methods
Added pregenerated certs

tests/test_acm/test_acm.py

@@ -0,0 +1,32 @@
+from __future__ import unicode_literals
+
+import os
+import boto3
+import sure  # noqa
+
+from botocore.exceptions import ClientError
+
+from moto import mock_acm
+
+
+RESOURCE_FOLDER = os.path.join(os.path.dirname(__file__), 'resources')
+_GET_RESOURCE = lambda x: open(os.path.join(RESOURCE_FOLDER, x), 'rb').read()
+CA_CRT = _GET_RESOURCE('ca.pem')
+CA_KEY = _GET_RESOURCE('ca.key')
+SERVER_CRT = _GET_RESOURCE('star_moto_com.pem')
+SERVER_CRT_BAD = _GET_RESOURCE('star_moto_com-bad.pem')
+SERVER_KEY = _GET_RESOURCE('star_moto_com.key')
+
+
+@mock_acm
+def test_import_certificate():
+    client = boto3.client('acm', region_name='eu-central-1')
+
+    resp = client.import_certificate(
+        Certificate=SERVER_CRT,
+        PrivateKey=SERVER_KEY,
+        CertificateChain=CA_CRT
+    )
+    resp = client.get_certificate(CertificateArn=resp['CertificateArn'])
+
+    print(resp)