Rearrange System Backend Test Cases and Ensure They're Filled Out (#276)

* Move sys methods into new class/file

* Bonus better error message

* Use assertEqual in place of bare assert

* Use assertTrue in place of bare assert

* Use assertFalse in place of bare assert

* Use assertNotEqual in place of bare assert

* Use assertGreater in place of bare assert

* Use assertNotIn in place of bare assert

* Use assertIn in place of bare assert

* Use assertIsNone in place of bare assert

* Add test for audit_hash method

* Fix docstring rtype

* Add test_get_secret_backend_tuning

* Fill out docstring

* add test_get_backed_up_keys

* Add v0.11.0 tests while getting things sorted

.travis.yml

@@ -18,6 +18,11 @@ matrix:
       env:
         - TOXENV=py27
         - VAULT_VERSION=0.10.4
+    - name: 'Python v2.7, Vault v0.11.0 - Integration/Unit Tests'
+      python: '2.7'
+      env:
+        - TOXENV=py27
+        - VAULT_VERSION=0.11.0
     - name: 'Python v2.7, Vault v0.11.1 - Integration/Unit Tests'
       python: '2.7'
       env:
@@ -47,6 +52,11 @@ matrix:
       env:
         - TOXENV=py27
         - VAULT_VERSION=0.10.4
+    - name: 'Python v3.6, Vault v0.11.0 - Integration/Unit Tests'
+      python: '3.6'
+      env:
+        - TOXENV=py27
+        - VAULT_VERSION=0.11.0
     - name: 'Python v3.6, Vault v0.11.1 - Integration/Unit Tests'
       python: '3.6'
       env:
@@ -62,11 +72,21 @@ matrix:
       env:
         - TOXENV=py27-flake8
   allow_failures:
+    - name: 'Python v2.7, Vault v0.11.0 - Integration/Unit Tests'
+      python: '2.7'
+      env:
+        - TOXENV=py27
+        - VAULT_VERSION=0.11.0
     - name: 'Python v2.7, Vault HEAD ref - Integration/Unit Tests'
       python: '2.7'
       env:
         - TOXENV=py27
         - VAULT_VERSION=HEAD
+    - name: 'Python v3.6, Vault v0.11.0 - Integration/Unit Tests'
+      python: '3.6'
+      env:
+        - TOXENV=py27
+        - VAULT_VERSION=0.11.0
     - name: 'Python v3.6, Vault HEAD ref - Integration/Unit Tests'
       python: '3.6'
       env: