【Tips】Ubuntuへのsqlite3 gemインストール時に発生しうるエラーへの対処

# 問題
## 入力
```sh
gem install sqlite3 -v '1.4.1'
```

## 出力
```sh
Building native extensions. This could take a while...
/home/【ユーザー名】/.anyenv/envs/rbenv/versions/2.6.3/lib/ruby/2.6.0/rubygems/ext/builder.rb:76: warning: Insecure world writable dir /home/【ユーザー名】/.anyenv/envs/rbenv/versions in PATH, mode 040777
ERROR:  Error installing sqlite3:
        ERROR: Failed to build gem native extension.

    current directory: /home/【ユーザー名】/.anyenv/envs/rbenv/versions/2.6.3/lib/ruby/gems/2.6.0/gems/sqlite3-1.4.1/ext/sqlite3
/home/【ユーザー名】/.anyenv/envs/rbenv/versions/2.6.3/bin/ruby -I /home/【ユーザー名】/.anyenv/envs/rbenv/versions/2.6.3/lib/ruby/2.6.0 -r ./siteconf20191109-13641-qybk8d.rb extconf.rb
/home/【ユーザー名】/.anyenv/envs/rbenv/versions/2.6.3/lib/ruby/2.6.0/mkmf.rb:1565: warning: Insecure world writable dir /home/【ユーザー名】/.anyenv/envs/rbenv/versions in PATH, mode 040777
checking for sqlite3.h... no
sqlite3.h is missing. Try 'brew install sqlite3',
'yum install sqlite-devel' or 'apt-get install libsqlite3-dev'
and check your shared library search path (the
location where your sqlite3 shared library is located).
*** extconf.rb failed ***
Could not create Makefile due to some reason, probably lack of necessary
libraries and/or headers.  Check the mkmf.log file for more details.  You may
need configuration options.

Provided configuration options:
        --with-opt-dir
        --without-opt-dir
        --with-opt-include
        --without-opt-include=${opt-dir}/include
        --with-opt-lib
        --without-opt-lib=${opt-dir}/lib
        --with-make-prog
        --without-make-prog
        --srcdir=.
        --curdir
        --ruby=/home/【ユーザー名】/.anyenv/envs/rbenv/versions/2.6.3/bin/$(RUBY_BASE_NAME)
        --with-sqlcipher
        --without-sqlcipher
        --with-sqlite3-config
        --without-sqlite3-config
        --with-pkg-config
        --without-pkg-config
        --with-sqlcipher
        --without-sqlcipher
        --with-sqlite3-dir
        --without-sqlite3-dir
        --with-sqlite3-include
        --without-sqlite3-include=${sqlite3-dir}/include
        --with-sqlite3-lib
        --without-sqlite3-lib=${sqlite3-dir}/lib

To see why this extension failed to compile, please check the mkmf.log which can be found here:

  /home/【ユーザー名】/.anyenv/envs/rbenv/versions/2.6.3/lib/ruby/gems/2.6.0/extensions/x86_64-linux/2.6.0-static/sqlite3-1.4.1/mkmf.log

extconf failed, exit code 1

Gem files will remain installed in /home/【ユーザー名】/.anyenv/envs/rbenv/versions/2.6.3/lib/ruby/gems/2.6.0/gems/sqlite3-1.4.1 for inspection.
Results logged to /home/【ユーザー名】/.anyenv/envs/rbenv/versions/2.6.3/lib/ruby/gems/2.6.0/extensions/x86_64-linux/2.6.0-static/sqlite3-1.4.1/gem_make.out
```

# 環境
- Windows Subsystem for Linux (WSL)
    * Ubuntu 18.04 LTS
- anyenv
    * rbenv 1.1.2-4-g577f046
        + ruby 2.6.3p62 (2019-04-16 revision 67580) [x86_64-linux]

# 原因：SQLite3の開発用ライブラリ不足
native extensionとして必要なSQLiteに関連するライブラリがOSにインストールされていない。

# 解決方法
エラーメッセージに書かれているとおり、`libsqlite3-dev`を`apt install`すれば良い。他環境に関しても同様に、OS Xの`brew`であれば`brew install sqlite3`、CentOSやAmazon Linux等RedHut系の`yum`で管理されているLinuxであれば`yum install sqlite-devel`が必要。

```sh
sudo apt install libsqlite3-dev
gem install sqlite3 -v '1.4.1'
```