Restrict amount of data beiging posted Issue #172

[BraunRudolf]

Pull Request

Description

Add check of content_lenght to main.post_pv_actual (limit 1 MB)

Add test_post_too_large_pv_actual

Fixes #172

How Has This Been Tested?

Unit-Test

Checklist:

• [x] My code follows OCF's coding style guidelines
• [x] I have performed a self-review of my own code
• [ ] I have made corresponding changes to the documentation
• [x] I have added tests that prove my fix is effective or that my feature works
• [x] I have checked my code and corrected any misspellings

[BraunRudolf]

Should the limit be mentioned in the doc string?

[peterdudfield]

@BraunRudolf do you mind fixing the lint error here?

[BraunRudolf]

Of course not! I'll take a look.