Update README.md

Author: martinssipenko

README.md

@@ -25,7 +25,7 @@ with different releases of PHPUnit and PHP. The following table should give an
 easy overview:
 
 | PSR-7 assertion version | PHPUnit 4 | PHPUnit 5 | PHPUnit 6 | PHPUnit 7 | PHPUnit 8 |
-| ----------------------- | --------- | --------- | --------- | --------- |
+| ----------------------- | --------- | --------- | --------- | --------- | --------- |
 | v1 (branch `v1`), **unsupported** | :white_check_mark: | :white_check_mark: | :no_entry_sign: | :no_entry_sign: | :no_entry_sign: |
 | v2 (branch `v2`) | :no_entry_sign: | :no_entry_sign: | :white_check_mark: | :no_entry_sign: | :no_entry_sign: |
 | v3 (branch `v3`) | :no_entry_sign: | :no_entry_sign: | :no_entry_sign: | :white_check_mark: | :no_entry_sign: |