Docker: Add PULL and FETCH parameters

README.md

 
     docker run -e TEST_DATABASE_ENGINE=postgresql -e CHECKOUT=<branch_or_commit_name> tracim:tests
 
+##### Other parameters (environment variables)
+
+* FETCH: (0 or 1) Apply a ``git fetch origin`` on tracim repository
+* PULL: (0 or 1) Apply a ``git pull origin master`` on tracim repository to set tracim on latest master branch
+
 #### Run Prod/dev containers
 
 Environment variables are:

docker/Debian_Tests/entrypoint.sh

 #
 # * TEST_DATABASE_ENGINE (values: postgresql, mysql, sqlite)
 # * CHECKOUT (values: a commit or branch name)
+# * PULL (values: 0 or 1)
+# * FETCH (values: 0 or 1)
 #
 
+# Default values
+FETCH=${FETCH:=1}
+PULL=${PULL:=1}
+
+# If PULL is set, change repository HEAD
+if [ "$FETCH" = 1 ]; then
+    cd /tracim && git fetch origin
+fi
+
+
+# If PULL is set, change repository HEAD
+if [ "$PULL" = 1 ]; then
+    cd /tracim && git pull origin master
+fi
+
 # If CHECKOUT is set, change repository HEAD
 if [ -n "$CHECKOUT" ]; then
     cd /tracim && git checkout ${CHECKOUT}