Add coreutils to installed apk to fix issue

see issue vishnubob/wait-for-it#71
also reduced the wait time to 30seconds

Dockerfile

@@ -6,7 +6,7 @@ LABEL Maintainer="Jh" \
 
 # Environment variables
 ENV APP_NAME GO Url Shortener
-ENV APP_PROTOCOL https://
+ENV APP_PROTOCOL http://
 ENV DB_PORT 3306
 ENV DB_DATABASE polr
 ENV DB_USERNAME polr
@@ -15,7 +15,7 @@ ENV POLR_BASE 62
 # Install packages
 RUN apk --no-cache add gettext git php7 php7-fpm php7-pdo php7-mysqli php7-json php7-openssl php7-curl \
     php7-zlib php7-xml php7-phar php7-intl php7-dom php7-xmlreader php7-ctype \
-    php7-mbstring php7-gd php7-xmlwriter php7-tokenizer php7-pdo_mysql php7-memcached nginx supervisor curl bash
+    php7-mbstring php7-gd php7-xmlwriter php7-tokenizer php7-pdo_mysql php7-memcached nginx supervisor curl bash coreutils
 
 # Configure nginx
 COPY config/nginx.conf /etc/nginx/nginx.conf
@@ -63,4 +63,4 @@ COPY seeders/AdminSeeder.php AdminSeeder_withoutEnv.php
 RUN apk del git
 
 EXPOSE 80
-ENTRYPOINT /wait-for-it.sh $DB_HOST:$DB_PORT --strict --timeout=120 -- /start.sh
+ENTRYPOINT /wait-for-it.sh $DB_HOST:$DB_PORT --strict --timeout=30 -- /start.sh