Update Dockerfile to decrease docker image size

scripts/Dockerfile

@@ -9,8 +9,11 @@ RUN apk add git g++ build-base linux-headers cmake && \
     cmake . && \
     make -j4 && \
     mv subconverter base/ && \
-    apk add curl yaml-cpp libevent && \
-    apk del git gcc g++ build-base linux-headers cmake libressl-dev curl-dev rapidjson-dev libevent-dev yaml-cpp-dev
+	mv base ../ && \
+	cd .. && \
+	rm -rf subconverter && \
+    apk add curl yaml-cpp libevent libpcrecpp && \
+    apk del git gcc g++ build-base linux-headers cmake libressl-dev curl-dev rapidjson-dev libevent-dev pcre-dev yaml-cpp-dev
 
 # set entry
-CMD /subconverter/base/subconverter
+CMD /base/subconverter