Add jpeg support in gd

Dockerfile

@@ -158,7 +158,14 @@ RUN echo @testing http://nl.alpinelinux.org/alpine/edge/testing >> /etc/apk/repo
     icu-dev \
     libpq \
     libxslt-dev \
-    libffi-dev &&\
+    libffi-dev \
+    freetype-dev \
+    libjpeg-turbo-dev && \
+    docker-php-ext-configure gd \
+      --with-gd \
+      --with-freetype-dir=/usr/include/ \
+      --with-png-dir=/usr/include/ \
+      --with-jpeg-dir=/usr/include/ && \
     #curl iconv session
     docker-php-ext-install pdo_mysql mysqli mcrypt gd exif intl xsl json soap dom zip && \
     mkdir -p /etc/nginx && \