Do apt-get install incrementally

Otherwise, Travis CI failed because "No output has been received in the
last 10m0s".

Dockerfile

@@ -2,7 +2,35 @@ FROM ubuntu:17.04
 RUN apt-get update && apt-get upgrade -y
 RUN apt-get -qq install -y apt-utils > /dev/null
 RUN apt-get -qq install -y moreutils
-RUN chronic apt-get -qq install -y afnix algol68g aplus-fsf aspectc++ aspectj asymptote ats2-lang bash bc bf bison bsdgames clisp clojure cmake coffeescript dafny dc ecere-dev elixir emacs24 erlang f2c fish flex fp-compiler fsharp g++ gambas3-script gap gawk gcc gdb gdc genius gforth gfortran ghc ghostscript gnat gnu-smalltalk gnuplot gobjc golang gpt gri groff groovy guile-2.0 gzip haxe icont iconx intercal iverilog jasmin-sable jq julia ksh libgd-dev libpng-dev lisaac livescript llvm lua5.3 m4 make maxima minizinc mlton mono-devel mono-mcs mono-vbnc nasm neko nescc nickle nim node-typescript nodejs ocaml octave open-cobol openjdk-8-jdk pakcs pari-gp parser3-cgi perl php-cli pike8.0 python r-base rakudo ratfor rc regina-rexx ruby ruby-mustache rustc scala scilab sed slsh spin squirrel3 swi-prolog tcl tcsh valac vim xsltproc yabasic yorick zoem zsh && apt-get clean
+RUN chronic apt-get -qq install -y afnix algol68g aplus-fsf aspectc++ && chronic apt-get clean
+RUN chronic apt-get -qq install -y aspectj asymptote ats2-lang bash && chronic apt-get clean
+RUN chronic apt-get -qq install -y bc bf bison bsdgames && chronic apt-get clean
+RUN chronic apt-get -qq install -y clisp clojure cmake coffeescript && chronic apt-get clean
+RUN chronic apt-get -qq install -y dafny dc ecere-dev elixir && chronic apt-get clean
+RUN chronic apt-get -qq install -y emacs24 erlang f2c fish && chronic apt-get clean
+RUN chronic apt-get -qq install -y flex fp-compiler fsharp g++ && chronic apt-get clean
+RUN chronic apt-get -qq install -y gambas3-script gap gawk gcc && chronic apt-get clean
+RUN chronic apt-get -qq install -y gdb gdc genius gforth && chronic apt-get clean
+RUN chronic apt-get -qq install -y gfortran ghc ghostscript gnat && chronic apt-get clean
+RUN chronic apt-get -qq install -y gnu-smalltalk gnuplot gobjc golang && chronic apt-get clean
+RUN chronic apt-get -qq install -y gpt gri groff groovy && chronic apt-get clean
+RUN chronic apt-get -qq install -y guile-2.0 gzip haxe icont && chronic apt-get clean
+RUN chronic apt-get -qq install -y iconx intercal iverilog jasmin-sable && chronic apt-get clean
+RUN chronic apt-get -qq install -y jq julia ksh libgd-dev && chronic apt-get clean
+RUN chronic apt-get -qq install -y libpng-dev lisaac livescript llvm && chronic apt-get clean
+RUN chronic apt-get -qq install -y lua5.3 m4 make maxima && chronic apt-get clean
+RUN chronic apt-get -qq install -y minizinc mlton mono-devel mono-mcs && chronic apt-get clean
+RUN chronic apt-get -qq install -y mono-vbnc nasm neko nescc && chronic apt-get clean
+RUN chronic apt-get -qq install -y nickle nim node-typescript nodejs && chronic apt-get clean
+RUN chronic apt-get -qq install -y ocaml octave open-cobol openjdk-8-jdk && chronic apt-get clean
+RUN chronic apt-get -qq install -y pakcs pari-gp parser3-cgi perl && chronic apt-get clean
+RUN chronic apt-get -qq install -y php-cli pike8.0 python r-base && chronic apt-get clean
+RUN chronic apt-get -qq install -y rakudo ratfor rc regina-rexx && chronic apt-get clean
+RUN chronic apt-get -qq install -y ruby ruby-mustache rustc scala && chronic apt-get clean
+RUN chronic apt-get -qq install -y scilab sed slsh spin && chronic apt-get clean
+RUN chronic apt-get -qq install -y squirrel3 swi-prolog tcl tcsh && chronic apt-get clean
+RUN chronic apt-get -qq install -y valac vim xsltproc yabasic && chronic apt-get clean
+RUN chronic apt-get -qq install -y yorick zoem zsh && chronic apt-get clean
 ENV PATH /usr/games:$PATH
 ADD . /usr/local/share/quine-relay
 WORKDIR /usr/local/share/quine-relay

src/Dockerfile.gen.rb

@@ -10,7 +10,9 @@
 dockerfile << "RUN apt-get update && apt-get upgrade -y"
 dockerfile << "RUN apt-get -qq install -y apt-utils > /dev/null"
 dockerfile << "RUN apt-get -qq install -y moreutils"
-dockerfile << "RUN chronic apt-get -qq install -y #{ apts.join(" ") } && apt-get clean"
+apts.each_slice(4) do |apt|
+  dockerfile << "RUN chronic apt-get -qq install -y #{ apt.join(" ") } && chronic apt-get clean"
+end
 dockerfile << "ENV PATH /usr/games:$PATH"
 dockerfile << "ADD . /usr/local/share/quine-relay"
 dockerfile << "WORKDIR /usr/local/share/quine-relay"