Add .gitreview and .zuul.yaml files

Also pinned charm-tools 2.8.3.
Also made necessary changes for charm-tools>=2.8, because
the default build output folder has changed.

Change-Id: I3f86e76388b274cd4c4d330c2612b633a9b19664

.gitreview

@@ -0,0 +1,4 @@
+[gerrit]
+host=review.opendev.org
+port=29418
+project=openstack/charm-magnum-dashboard.git

.zuul.yaml

@@ -0,0 +1,4 @@
+- project:
+    templates:
+      - openstack-python3-charm-jobs
+      - openstack-cover-jobs

requirements.txt

@@ -9,7 +9,7 @@
 setuptools<50.0.0  # https://github.com/pypa/setuptools/commit/04e3df22df840c6bb244e9b27bc56750c44b7c85
 
 # Build requirements
-charm-tools>=2.4.4
+charm-tools==2.8.3
 
 # Workaround until https://github.com/juju/charm-tools/pull/589 gets
 # published

tox.ini

@@ -28,7 +28,7 @@ deps =
 [testenv:build]
 basepython = python3
 commands =
-    charm-build --log-level DEBUG -o {toxinidir}/build src {posargs}
+    charm-build --log-level DEBUG -o {toxinidir}/build/builds src {posargs}
 
 [testenv:py3]
 basepython = python3