Update cbmc-builder alpine container

Author: Vlastimil Zeman

.travis.yml

@@ -48,9 +48,9 @@ jobs:
       services:
         - docker
       before_install:
-        - docker pull diffblue/cbmc-builder:alpine-0.0.1
+        - docker pull diffblue/cbmc-builder:alpine-0.0.3
       env:
-        - PRE_COMMAND="docker run -v ${TRAVIS_BUILD_DIR}:/cbmc -v ${HOME}/.ccache:/root/.ccache diffblue/cbmc-builder:alpine-0.0.1"
+        - PRE_COMMAND="docker run -v ${TRAVIS_BUILD_DIR}:/cbmc -v ${HOME}/.ccache:/root/.ccache diffblue/cbmc-builder:alpine-0.0.3"
         - COMPILER="ccache g++"
 
     # OS X using g++