Issue 72 fix git language bug

[yeraydavidrodriguez]

This PR solves the GIT language issues described on #72 .

The problems were:

• A localized string search on the git-repo::hasCommits method. This was replaced by examining the returning error code from a git log command.

• Relying on SimpleGit to check if a dir contains an initialized repo. SimpleGit does not perform this test reliably (as described here), we fixed it by examining the returning error code from a git status command.

Additionally, we perform sanitization on the shell commands (by checking if the string passed to it is an actual dir) and we include this same test in the gitRepoDir class initialization.

[github-actions]

MegaLinter status: ⚠️ WARNING

Descriptor	Linter	Files	Fixed	Errors	Elapsed time
✅ ACTION	actionlint	5		0	0.17s
✅ COPYPASTE	jscpd	yes		no	1.85s
✅ CREDENTIALS	secretlint	yes		no	1.03s
✅ GIT	git_diff	yes		no	0.02s
✅ JAVASCRIPT	standard	1	0	0	1.49s
✅ JSON	eslint-plugin-jsonc	7	0	0	1.01s
✅ JSON	jsonlint	7		0	2.02s
✅ JSON	prettier	7	0	0	1.38s
✅ JSON	v8r	7		0	8.32s
⚠️ MARKDOWN	markdownlint	2	0	1	0.4s
✅ MARKDOWN	markdown-link-check	2		0	2.36s
✅ MARKDOWN	markdown-table-formatter	2	0	0	0.35s
✅ SPELL	cspell	81		0	3.92s
✅ SPELL	misspell	81	0	0	0.17s
✅ TYPESCRIPT	eslint	54	0	0	14.38s
✅ YAML	prettier	8	0	0	1.65s
✅ YAML	v8r	8		0	9.47s
✅ YAML	yamllint	8		0	0.34s

See errors details in artifact MegaLinter reports on CI Job page

[josecelano]

hi @yeraydavidrodriguez it looks good to me but make sure we do not have any problem with relative paths.