Added tzdata package to alpine variants.

Closes: #204
Closes: #149
Closes: #150

mainline/alpine-perl/Dockerfile

@@ -133,6 +133,10 @@ RUN GPG_KEYS=B0F4253373F8F6F510D42178520A9993A1C052F8 \
 	&& apk del .gettext \
 	&& mv /tmp/envsubst /usr/local/bin/ \
 	\
+	# Bring in tzdata so users could set the timezones through the environment
+	# variables
+	&& apk add --no-cache tzdata \
+	\
 	# forward request and error logs to docker log collector
 	&& ln -sf /dev/stdout /var/log/nginx/access.log \
 	&& ln -sf /dev/stderr /var/log/nginx/error.log

mainline/alpine/Dockerfile

@@ -128,6 +128,10 @@ RUN GPG_KEYS=B0F4253373F8F6F510D42178520A9993A1C052F8 \
 	&& apk del .gettext \
 	&& mv /tmp/envsubst /usr/local/bin/ \
 	\
+	# Bring in tzdata so users could set the timezones through the environment
+	# variables
+	&& apk add --no-cache tzdata \
+	\
 	# forward request and error logs to docker log collector
 	&& ln -sf /dev/stdout /var/log/nginx/access.log \
 	&& ln -sf /dev/stderr /var/log/nginx/error.log