fix Dockerfile formatting

Dockerfile

@@ -3,18 +3,18 @@ FROM kong:2.8.4-alpine
 USER root
 ARG VERSION
 ENV LUA_PATH=/usr/local/share/lua/5.1/?.lua;; \
-    DD_SERVICE=kong \
-    DD_ENV=prod \
-    DD_VERSION=$VERSION
+  DD_SERVICE=kong \
+  DD_ENV=prod \
+  DD_VERSION=$VERSION
 
 RUN apk add --no-cache wget curl httpie && \
-    wget -q https://raw.githubusercontent.com/tschaume/kong/feat/persistent-cookie/kong/plugins/session/schema.lua && \
-    mv schema.lua /usr/local/share/lua/5.1/kong/plugins/session/ && \
-    wget -q https://raw.githubusercontent.com/tschaume/kong/feat/persistent-cookie/kong/plugins/session/session.lua && \
-    mv session.lua /usr/local/share/lua/5.1/kong/plugins/session/ && \
-    chmod -R a+r /usr/local/share/lua/5.1/kong/plugins/session
+  wget -q https://raw.githubusercontent.com/tschaume/kong/feat/persistent-cookie/kong/plugins/session/schema.lua && \
+  mv schema.lua /usr/local/share/lua/5.1/kong/plugins/session/ && \
+  wget -q https://raw.githubusercontent.com/tschaume/kong/feat/persistent-cookie/kong/plugins/session/session.lua && \
+  mv session.lua /usr/local/share/lua/5.1/kong/plugins/session/ && \
+  chmod -R a+r /usr/local/share/lua/5.1/kong/plugins/session
 
-WORKDIR grant-proxy-oauth
+WORKDIR /grant-proxy-oauth
 COPY handler.lua .
 COPY schema.lua .
 COPY kong-grant-proxy-oauth-0.0-0.rockspec .