Correct the file permission

Start by checking the tracked modes with ls -l for composer.json, .gitignore, LICENSE.md, phpunit.xml, and the PHP files under tests/CLI. Compare those modes with the other non-executable project files, then verify that the listed files no longer have executable permission.

As title, it seems that some files don't have correct file permissions.

For example, we can see the following command output:

$ ls -al
total 104
drwxrwxr-x   6 lee lee  4096 Oct  4 09:50 ./
drwx------ 554 lee lee 36864 Oct  4 09:50 ../
-rw-rw-r--   1 lee lee  3346 Oct  4 09:50 CODE_OF_CONDUCT.md
-rwxrwxr-x   1 lee lee   792 Oct  4 09:50 composer.json*
-rw-rw-r--   1 lee lee  4724 Oct  4 09:50 CONTRIBUTING.md
drwxrwxr-x   8 lee lee  4096 Oct  4 09:50 .git/
drwxrwxr-x   3 lee lee  4096 Oct  4 09:50 .github/
-rwxrwxr-x   1 lee lee    53 Oct  4 09:50 .gitignore*
-rwxrwxr-x   1 lee lee  1076 Oct  4 09:50 LICENSE.md*
-rw-rw-r--   1 lee lee   563 Oct  4 09:50 phpcs.xml
-rwxrwxr-x   1 lee lee   499 Oct  4 09:50 phpunit.xml*
-rw-rw-r--   1 lee lee   444 Oct  4 09:50 psalm.xml
-rw-rw-r--   1 lee lee  3870 Oct  4 09:50 README.md
drwxrwxr-x   3 lee lee  4096 Oct  4 09:50 src/
drwxrwxr-x   4 lee lee  4096 Oct  4 09:50 tests/
-rw-rw-r--   1 lee lee   251 Oct  4 09:50 .travis.yml

ls tests/CLI/ -al 
drwxrwxr-x 2 lee lee 4096 Oct  4 09:57 ./
drwxrwxr-x 4 lee lee 4096 Oct  4 09:57 ../
-rwxrwxr-x 1 lee lee 7681 Oct  4 09:57 CLITest.php*
-rwxrwxr-x 1 lee lee 3445 Oct  4 09:57 ConsoleTest.php*
-rwxrwxr-x 1 lee lee 1764 Oct  4 09:57 TaskTest.php*

As we can see, composer.json, .gitignore, LICENSE.md and phpunit.xml files should not have executable permission.

And some PHP files in the tests/CLI folder also have the same issue.

And they should be fixed.