Show progress of repo cloning (#230)

Show progress of 'git clone' command so that it is apparent the command
is running and the program is not stuck. This is especially helpful if
the user is running on a slow internet connection.

Signed-off-by: Grigoris Thanasoulas <gregth@arrikto.com>

Signed-off-by: Grigoris Thanasoulas <gregth@arrikto.com>

openapi/openapi-generator/Dockerfile

@@ -24,7 +24,7 @@ ARG OPENAPI_GENERATOR_USER_ORG=OpenAPITools
 # Check out specific commit of openapi-generator
 RUN mkdir /source && \
     cd /source && \
-    git clone -n https://github.com/${OPENAPI_GENERATOR_USER_ORG}/openapi-generator.git && \
+    git clone --progress -n https://github.com/${OPENAPI_GENERATOR_USER_ORG}/openapi-generator.git && \
     cd openapi-generator && \
     git checkout $OPENAPI_GENERATOR_COMMIT