minor #428 Update supported branches in README file and PR template (GSadee)

This PR was merged into the 1.4 branch.

Discussion
----------

| Q               | A
| --------------- | -----
| Branch?         | 1.4
| Bug fix?        | no
| New feature?    | no
| Related tickets | 


Commits
-------

4fc1d54 Update supported branches in README file
4fb850f Update PR template
6cbbd85 Add conflict to behat/mink-selenium2-driver to fix the builds

Author: GSadee

.github/PULL_REQUEST_TEMPLATE.md

@@ -1,6 +1,6 @@
 | Q               | A
 | --------------- | -----
-| Branch?         | 1.3 (security fixes), 1.4 (bug fixes, improvements), 1.5 (new features)
+| Branch?         | 1.4 (security fixes), 1.5 (bug fixes, improvements), 1.6 (new features)
 | Bug fix?        | no/yes
 | New feature?    | no/yes
 | Related tickets | fixes #X, partially #Y, mentioned in #Z

CONFLICTS.md

@@ -0,0 +1,9 @@
+# CONFLICTS
+
+This document explains why certain conflicts were added to `composer.json` and
+references related issues.
+
+- `behat/mink-selenium2-driver:>=1.7.0`:
+
+  This version adds strict type to the `Behat\Mink\Driver\Selenium2Driver::visit($url)` method
+  which causes a fatal error because the method signature is no longer compatible with the parent class.

README.md

@@ -130,9 +130,9 @@ Tagged services would be executed according to their priority (descending).
 
 ## Supported branches
 
-* `1.3` (v1.3.*) - security fixes
-* `1.4` (v1.4.*) - bug fixes, improvements
-* `1.5` (v1.5.*) - new features
+* `1.4` (v1.4.*) - security fixes
+* `1.5` (v1.5.*) - bug fixes, improvements
+* `1.6` (v1.6.*) - new features
 * `2.0` (v2.0.*) - new features, removing deprecations, BC breaks
 
 ## Security issues

composer.json

@@ -56,6 +56,9 @@
         "symfony/web-profiler-bundle": "^5.4 || ^6.0",
         "symfony/webpack-encore-bundle": "^1.15"
     },
+    "conflict": {
+        "behat/mink-selenium2-driver": ">=1.7.0"
+    },
     "autoload": {
         "psr-4": {
             "Sylius\\RefundPlugin\\": "src/",