v1.0.2: Upgrade version of SF Property Access to 5 and 6

• Enable this packages for symfony/property-access at versions ^5.0 and ^6.0
• Upgrade versions of dev-dependency for phpunit to ^6.3|^7.0|^8.0|^9.0

v1.0.1: Adding PHP 7.2 to Travis config, some code improvements. (#7)

* Travis config updated.
* Some fixes for PHPStan.
* Some fixes.

v1.0.0: Merge pull request #6 from mimol91/patch-2

Update dependency

v1.0.0-alpha.6: Merge pull request #2 from mimol91/meaningfullExample

Use more real-life example in Readme,

v1.0.0-alpha.5

Basic tests.

v1.0.0-alpha.4

Minor fixes.

v1.0.0-alpha.3

README extended.

v1.0.0-alpha.2

Badges in README fixed.

v1.0.0-alpha.1

Description adjusted.