[unittest] Configure the CI jobs

.gitlab-ci.yml

+image: gepgitlab.laas.fr:4567/Gepetto/example-robot-data
+
+test:
+  script:
+    - cd unittest && python test_all.py

unittest/test_all.py

+import unittest
+import sys
+
+testmodules = [
+  'test_load',
+]
+
+suite = unittest.TestSuite()
+
+for t in testmodules:
+  try:
+    # If the module defines a suite() function, call it to get the suite.
+    mod = __import__(t, globals(), locals(), ['suite'])
+    suitefn = getattr(mod, 'suite')
+    suite.addTest(suitefn())
+  except (ImportError, AttributeError):
+    # else, just load all the test cases from the module.
+    suite.addTest(unittest.defaultTestLoader.loadTestsFromName(t))
+
+result = unittest.TextTestRunner().run(suite)
+sys.exit(len(result.errors) + len(result.failures))