Add entrypoint script with wait function for db.

app/Dockerfile

@@ -17,4 +17,10 @@ RUN pipenv install --skip-lock --system --dev
 # copy project
 COPY . /usr/src/app/
 
+# add wait for it
+RUN git clone https://github.com/vishnubob/wait-for-it.git /wait-for-it
+RUN chmod a+x /wait-for-it/wait-for-it.sh
 
+# add entry point
+ADD ./django-entrypoint.sh /django-entrypoint.sh
+RUN chmod a+x /django-entrypoint.sh