Correction on prokka installation

for_tests/Dockerfile

@@ -33,9 +33,7 @@ RUN apt-get install -y\
         bioperl
 RUN git clone https://github.com/tseemann/prokka.git
 RUN /tmp/prokka/bin/prokka --setupdb
-RUN mv /tmp/prokka/bin/prokka /usr/local/bin
-RUN rm -r /tmp/prokka
-
+RUN ln -s /tmp/prokka/bin/prokka /usr/local/bin
 
 # Install mmseqs2
 WORKDIR /tmp