[ADD] Launch script: Change config to config.example to permit user to

keep its own configuration without any lost when fetching git repository

.gitignore

@@ -0,0 +1 @@
+config

launch.sh

@@ -15,6 +15,10 @@ POSTGRES_VERSION="9.5"
 GISSMO_DOCKER_NAME="gissmo"
 
 ## User
+if ! test -f config; then
+  echo "'config' file not found. Copy config.example to config one and try again!"
+  exit 1
+fi
 . config || exit 1
 
 ## Composed