Use c++17 by default

Dockerfile

@@ -3,6 +3,7 @@ COPY caide /home/caide
 COPY run.sh /home/run.sh
 WORKDIR /home
 RUN ./caide init
+COPY caide.ini caide.ini
 RUN ./caide problem basic
 RUN mkdir io
 RUN chmod +x run.sh

caide.ini

@@ -0,0 +1,21 @@
+[core]
+features:
+language: cpp
+
+[cpp]
+clang_options: -target,
+      i386-pc-mingw32,
+      -nostdinc,
+      -isystem,
+      /home/include/c++,
+      -isystem,
+      /home/include/c++/i686-w64-mingw32,
+      -isystem,
+      /home/include/crt,
+      -I,
+      /home/cpplib,
+      -std=c++1z,
+      -fparse-all-comments,
+      -DONLINE_JUDGE
+keep_macros: _WIN32,_WIN64,_MSC_VER,__GNUC__,__cplusplus
+max_consequent_empty_lines: 2