Update image dependencies

- Update NGINX to latest stable
- Update pngquant to latest stable
- Update ImageMagick to latest stable

Also, remove extra ruby install, it is no longer needed

image/base/Dockerfile

@@ -64,12 +64,10 @@ RUN mkdir /jemalloc-new && cd /jemalloc-new &&\
       tar -xjf jemalloc-5.1.0.tar.bz2 && cd jemalloc-5.1.0 && ./configure --prefix=/usr --with-install-suffix=5.1.0 && make build_lib && make install_lib &&\
       cd / && rm -rf /jemalloc-new
 
-RUN apt-get -y install ruby &&\
-    echo 'gem: --no-document' >> /usr/local/etc/gemrc &&\
+RUN echo 'gem: --no-document' >> /usr/local/etc/gemrc &&\
     mkdir /src && cd /src && git clone https://github.com/sstephenson/ruby-build.git &&\
     cd /src/ruby-build && ./install.sh &&\
-    cd / && rm -rf /src/ruby-build && (ruby-build 2.6.1 /usr/local) &&\
-    apt-get -y remove ruby
+    cd / && rm -rf /src/ruby-build && (ruby-build 2.6.1 /usr/local)
 
 RUN gem update --system
 

image/base/install-imagemagick

@@ -17,7 +17,7 @@ cd $WDIR/libpng
 make all && make install
 
 # Build and install ImageMagick
-wget -O $WDIR/ImageMagick.tar.gz "https://github.com/ImageMagick/ImageMagick/archive/7.0.8-6.tar.gz"
+wget -O $WDIR/ImageMagick.tar.gz "https://github.com/ImageMagick/ImageMagick/archive/7.0.8-23.tar.gz"
 IMDIR=$WDIR/$(tar tzf $WDIR/ImageMagick.tar.gz --wildcards "ImageMagick-*/configure" |cut -d/ -f1)
 tar zxf $WDIR/ImageMagick.tar.gz -C $WDIR
 cd $IMDIR

image/base/install-nginx

@@ -1,6 +1,6 @@
 #!/bin/bash
 set -e
-VERSION=1.15.0
+VERSION=1.15.8
 cd /tmp
 
 apt-get install -y autoconf

image/base/install-pngquant

@@ -1,5 +1,5 @@
 #!/bin/bash
-VERSION=2.12.1
+VERSION=2.12.2
 cd /tmp
 git clone -b $VERSION --single-branch https://github.com/pornel/pngquant
 cd pngquant