feat: add xray rest api (server/data-center) support (atlassian-api#559)

* feat: add xray rest api (server/data-center) support

This commits adds support for v1.0 of the Xray REST api for Server
and Data-Center. As of now, v2.0 does not cover all functionality
provided in the initial version, mainly related to test automation
(eg. import of test executions/...).

* docs: update documentation for the xray module

* fix: expose module correctly

Author: KevinDeJong-TomTom

CONTRIBUTING.rst

@@ -77,6 +77,8 @@ All methods based on docs from: https://developer.atlassian.com/docs/
     - https://developer.atlassian.com/platform/marketplace/rest
 * Crowd:
     - https://developer.atlassian.com/server/crowd/crowd-rest-apis/
+* Xray:
+    - https://docs.getxray.app/display/XRAY/REST+API
 * Others:
     - https://developer.atlassian.com/server/jira/platform/oauth/
     - https://confluence.atlassian.com/cloud/api-tokens-938839638.html

README.rst

@@ -81,6 +81,20 @@ Example to get your requests:
     data = sd.get_my_customer_requests()
     print(data)
 
+Using Xray (Test Management tool for Jira):
+
+.. code-block:: python
+
+    from atlassian import Xray
+
+    xr = Xray(
+           url='http://localhost:7990',
+            username='admin',
+            password='admin')
+    
+    data = xr.get_tests('TEST-001')
+    print(data)
+
 If you want to see the response in pretty print format JSON. Feel free for use construction like:
 
 .. code-block:: python

atlassian/__init__.py

@@ -7,6 +7,7 @@
 from .marketplace import MarketPlace
 from .portfolio import Portfolio
 from .service_desk import ServiceDesk
+from .xray import Xray
 
 __all__ = [
     'Confluence',
@@ -17,5 +18,6 @@
     'Stash',
     'Crowd',
     'ServiceDesk',
-    'MarketPlace'
+    'MarketPlace',
+    'Xray'
 ]