change comments place

Dockerfile

@@ -4,14 +4,16 @@ from ubuntu:16.04
 RUN apt-get update &&\
     apt-get -y upgrade
 
-# Install required packages
+# Install package needed
 RUN apt-get install -y \
-        pkg-config \
-        wget \
-        libpng-dev # required to install matplotlib \
-        libjpeg8-dev # required to install matplotlib\
-        libfreetype6-dev # required to install matplotlib\
+        wget
         python3-pip
+# Install packages required to install matplotlib
+RUN apt-get install -y \
+        pkg-config \
+        libpng-dev \
+        libjpeg8-dev \
+        libfreetype6-dev
 
 # Update pip
 RUN pip3 install --upgrade pip