Add code gen configuration

[kyuridenamida]

~/.atcodertools.tomlにコード生成用の設定ファイルを記述できるようにした。
一般的な名前のファイルなのは将来的にcodegenだけじゃなくて一般の設定とかもこのファイルで取り扱いたいため。

tomlファイルの例:

[codegen]
indent_type = 'space' # 'tab' or 'space'
indent_width = 4

現状で設定できるのは2つ

• indent_type スペース(space)もしくは(tab)を指定する
• indent_width 一回のインデントで指定したindent_typeが何回繰り返されるか

kyuridenamida@name:~/atcoder-tools$ ./atcoder-tools gen --help
usage: ./atcoder-tools gen [-h] [--without-login] [--workspace WORKSPACE]
                           [--lang LANG] [--template TEMPLATE]
                           [--replacement REPLACEMENT] [--parallel]
                           [--save-no-session-cache] [--config CONFIG]
                           contest_id

positional arguments:
  contest_id            contest ID (e.g. arc001)

optional arguments:
(省略)
  --config CONFIG       file path to your config file
                        [Default (Primary)] /home/kyuridenamida/.atcodertools.toml
                        [Default (Secondary)] /home/kyuridenamida/atcoder-tools/atcodertools/tools/atcodertools-default.toml

[codecov-io]

Codecov Report

Merging #52 into master will increase coverage by 0.02%.
The diff coverage is 93.61%.

@@            Coverage Diff             @@
##           master      #52      +/-   ##
==========================================
+ Coverage   91.04%   91.07%   +0.02%     
==========================================
  Files          31       32       +1     
  Lines        1541     1579      +38     
==========================================
+ Hits         1403     1438      +35     
- Misses        138      141       +3

Impacted Files	Coverage Δ
atcodertools/tools/submit.py	53.44% <ø> (ø)	⬆️
atcodertools/tools/tester.py	83.11% <ø> (ø)	⬆️
atcodertools/release_management/version_check.py	54.05% <100%> (ø)	⬆️
atcodertools/codegen/cpp_code_generator.py	94.23% <100%> (+0.11%)	⬆️
atcodertools/tools/envgen.py	81.57% <88.88%> (+0.41%)	⬆️
atcodertools/codegen/code_gen_config.py	95.45% <95.45%> (ø)

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update a2dd3b3...8dbb771. Read the comment docs.