[3.0] Remove v2 code from v3 branch (#1096)

Author: crazywhalecc

bin/spc-alpine-docker

@@ -122,7 +122,7 @@ COPY ./composer.* /app/
 ADD ./bin /app/bin
 RUN composer install --no-dev
 ADD ./config /app/config
-ADD ./spc.registry.json /app/spc.registry.json
+ADD ./spc.registry.yml /app/spc.registry.yml
 RUN bin/spc doctor --auto-fix
 RUN bin/spc install-pkg upx
 

bin/spc-gnu-docker

@@ -29,7 +29,6 @@
     },
     "autoload": {
         "psr-4": {
-            "SPC\\": "src/SPC",
             "StaticPHP\\": "src/StaticPHP",
             "Package\\": "src/Package"
         },