Add benchmarks to CI

docker/Dockerfile

@@ -35,7 +35,7 @@ RUN if [ "$debug" = 0 ]; then \
 
 ARG benchmarks=0
 RUN if [ "$benchmarks" != 0 ]; then \
-        echo "BENCH_OPTIONS=runtime-benchmarks" >>/root/dynenv; \
+        echo "BENCH_OPTIONS=--features\ runtime-benchmarks" >>/root/dynenv; \
     fi
 
 # Configure cross-build environment if need be
@@ -53,7 +53,7 @@ ARG chain="gdev"
 RUN set -x && \
     cat /root/dynenv && \
     . /root/dynenv && \
-    cargo build --locked $CARGO_OPTIONS --no-default-features --features  $BENCH_OPTIONS $chain --target "$RUST_ARCH_TRIPLET" && \
+    cargo build --locked $CARGO_OPTIONS --no-default-features $BENCH_OPTIONS --features $chain --target "$RUST_ARCH_TRIPLET" && \
     mkdir -p build && \
     mv target/$RUST_ARCH_TRIPLET/$TARGET_FOLDER/duniter build/