Merge branch 'ci' into 'master'

add some ci checking

See merge request !92

circle.yml

+version: 2
+
+jobs:
+    # Build Cyclus
+    build:
+        docker:
+            - image: rootproject/root-ubuntu16
+        working_directory: ~/CLASS
+        steps:
+            # Ensure your image has git (required by git to clone via SSH) so that CircleCI can clone your repo
+            - run: apt-get -qq update; apt-get -y install git openssh-client
+            - checkout
+            - run:
+                name: Build Docker Image
+                command: |
+                    ./install clean-build
+            - run:
+                name: save SHA to a file
+                command: echo $CIRCLE_SHA1 > .circle-sha
+            - save_cache:
+                key: v1-repo-{{ checksum ".circle-sha" }}
+                paths:
+                  - /root
+
+
+    # Test Jobs
+    unit_test:
+        docker:
+            - image: rootproject/root-ubuntu16
+        working_directory: ~/CLASS
+        steps:
+            - run:
+                name: save SHA to a file
+                command: echo $CIRCLE_SHA1 > .circle-sha
+            - restore_cache:
+                keys:
+                  - v1-repo-{{ checksum ".circle-sha" }}
+            - run:
+                name: Unit Test
+                command: ./install gtest; exit $?
+
+
+workflows:
+    version: 2 #Needed ?? (already on the top of the file)
+    build_and_test:
+        jobs:
+
+            # On a PR // All Branch
+            - build
+            - unit_test:
+                requires:
+                    - build