updating xacc fedora docker file

docker/fedora/Dockerfile

 from mccaskey/base-fedora-gcc6
-run dnf -y install spdlog libstdc++-static \
+run dnf -y install spdlog \
     https://github.com/ORNL-QCI/ScaffCC/releases/download/v2.0/scaffold-2.0-1.fc25.x86_64.rpm \
     && git clone --recursive https://github.com/ORNL-QCI/xacc \
     && rm -rf /projects/xacc/tpls/fire/.git \ 
-    && echo "export PATH=$PATH:/usr/local/scaffold" >> ~/.bashrc \
     && source /etc/bashrc && module load mpi/mpich-x86_64 && cd /projects/xacc && mkdir build \
-    && cd build && cmake .. && make && PATH=$PATH:/usr/local/scaffold ctest
+    && cd build && cmake .. && make && ctest