Minor tidying changes to Dockerfile.

Dockerfile

@@ -2,25 +2,16 @@ FROM ubuntu:rolling
 
 MAINTAINER Jens Renè Suckert <jens.suckert@gmail.com>
 
-RUN apt-get -y update && apt-get install -y --no-install-recommends  \
-		build-essential \
-		python \
-		git \
-		cmake \
-		qt5-default \
-		libqt5charts5-dev \
-		libqt5opengl5-dev \
-		--reinstall ca-certificates 
-
-# Are these packages needed?
-#		pkg-config \
-#		graphviz \
-#		libqt5sql5-sqlite \
-#		libqt5sql5-mysql \
-#		sudo \
-#		libqt5charts5 \
-#		libqt5opengl5 \
-#	&& echo 'user ALL=(ALL) NOPASSWD: ALL' >/etc/sudoers.d/user
+RUN apt-get -y update && \
+    apt-get install -y --no-install-recommends \
+        build-essential \
+        python \
+        git \
+        cmake \
+        qt5-default \
+        libqt5charts5-dev \
+        libqt5opengl5-dev \
+        --reinstall ca-certificates 
 
 RUN export uid=1000 gid=1000 && \
     mkdir -p /home/developer && \
@@ -31,17 +22,19 @@ RUN export uid=1000 gid=1000 && \
 #    echo "developer ALL=(ALL) NOPASSWD: ALL" > /etc/sudoers.d/developer && \
 #    chmod 0440 /etc/sudoers.d/developer && \
 
-
 USER developer
 ENV HOME /home/developer
 
-RUN cd $HOME && git clone https://github.com/spirit-code/spirit.git
+RUN cd $HOME && \
+    git clone https://github.com/spirit-code/spirit.git
+
+RUN cd $HOME/spirit && \
+    git checkout develop
+
+RUN cd $HOME/spirit && \
+    ./cmake.sh
 
 RUN cd $HOME/spirit && \
-    mkdir -p build && \
-    cd build && \
-    cmake .. && \
-    cd .. && \
-    ./make.sh
+    ./make.sh -j2
 
-CMD cd $HOME/spirit/ && ./spirit
+CMD cd $HOME/spirit && ./spirit