remove build artifacts from docker image (#79)

Dockerfile

@@ -4,7 +4,9 @@ COPY . /home/bap/cwe_checker/
 
 RUN sudo chown -R bap:bap /home/bap/cwe_checker \
     && cd /home/bap/cwe_checker \
-    && make clean && make all
+    && make all \
+    && cargo clean \
+    && dune clean
 
 WORKDIR /home/bap/cwe_checker
 

README.md

@@ -33,7 +33,7 @@ Another way is to get cwe_checker from the Ocaml package manager Opam. You can i
 If you plan to develop *cwe_checker*, it is recommended to build it using the provided `Makefile`. In this case you must ensure that all dependencies are fulfilled:
 -   Ocaml 4.07.1
 -   Opam 2.0.2
--   dune >= 1.6
+-   dune >= 2.0
 -   BAP (and its dependencies). Development on the master branch depends on the master branch of BAP which can be added with `opam repo add bap-testing git+https://github.com/BinaryAnalysisPlatform/opam-repository#testing` to the sources of the Opam package manager. The stable release of the *cwe_checker* depends on BAP 1.6.
 -   yojson >= 1.6.0
 -   ppx_deriving_yojson >= 3.5.1