ci: Increase CCACHE_SIZE in some builds on Travis

ci/test/00_setup_env_native_fuzz.sh

@@ -15,3 +15,4 @@ export RUN_FUNCTIONAL_TESTS=false
 export RUN_FUZZ_TESTS=true
 export GOAL="install"
 export BITCOIN_CONFIG="--enable-fuzz --with-sanitizers=fuzzer,address,undefined CC=clang CXX=clang++"
+export CCACHE_SIZE=200M