Remove explicit package versions from Dockerfile

It's using a stable version of Debian, so it's redundant to lock
packages to specific versions.

Author: MarkKoz

Dockerfile

@@ -5,16 +5,16 @@ WORKDIR /nsjail
 
 RUN apt-get -y update \
     && apt-get install -y \
-        bison=2:3.3.* \
-        flex=2.6.* \
-        g++=4:8.3.* \
-        gcc=4:8.3.* \
-        git=1:2.20.* \
-        libprotobuf-dev=3.6.* \
-        libnl-route-3-dev=3.4.* \
-        make=4.2.* \
-        pkg-config=0.29-6 \
-        protobuf-compiler=3.6.*
+        bison\
+        flex \
+        g++ \
+        gcc \
+        git \
+        libprotobuf-dev\
+        libnl-route-3-dev \
+        make \
+        pkg-config \
+        protobuf-compiler
 RUN git clone -b master --single-branch https://github.com/google/nsjail.git . \
     && git checkout dccf911fd2659e7b08ce9507c25b2b38ec2c5800
 RUN make
@@ -31,10 +31,10 @@ ENV PATH=/root/.local/bin:$PATH \
 
 RUN apt-get -y update \
     && apt-get install -y \
-        gcc=4:8.3.* \
-        git=1:2.20.* \
-        libnl-route-3-200=3.4.* \
-        libprotobuf17=3.6.* \
+        gcc \
+        git \
+        libnl-route-3-200 \
+        libprotobuf17 \
     && rm -rf /var/lib/apt/lists/*
 
 COPY --from=builder /nsjail/nsjail /usr/sbin/