Update README and delete obsolete code

Author: UnderGreen

README.md

@@ -13,15 +13,13 @@ MongoDB support matrix:
 
 | Distribution   | < MongoDB 3.4 |    MongoDB 3.6     |    MongoDB 4.0     |   MongoDB 4.2      |
 | -------------- | :-----------: | :----------------: | :----------------: | :----------------: |
-| Ubuntu 14.04   |  :no_entry:   | :white_check_mark: | :white_check_mark: |        :x:         |
 | Ubuntu 16.04   |  :no_entry:   | :white_check_mark: | :white_check_mark: | :white_check_mark: |
-| Ubuntu 18.04   |  :no_entry:   |        :x:         | :white_check_mark: | :white_check_mark: |
-| Debian 8.x     |  :no_entry:   | :white_check_mark: | :white_check_mark: |        :x:         |
+| Ubuntu 18.04   |  :no_entry:   | :white_check_mark: | :white_check_mark: | :white_check_mark: |
 | Debian 9.x     |  :no_entry:   | :white_check_mark: | :white_check_mark: | :white_check_mark: |
 | Debian 10.x    |  :no_entry:   |        :x:         |        :x:         | :white_check_mark: |
-| RHEL 6.x       |  :no_entry:   | :white_check_mark: | :white_check_mark: | :white_check_mark: |
 | RHEL 7.x       |  :no_entry:   | :white_check_mark: | :white_check_mark: | :white_check_mark: |
-| Amazon Linux 2 |  :no_entry:   |        :x:         | :white_check_mark: | :white_check_mark: |
+| RHEL 8.x       |  :no_entry:   | :white_check_mark: | :white_check_mark: | :white_check_mark: |
+| Amazon Linux 2 |  :no_entry:   | :white_check_mark: | :white_check_mark: | :white_check_mark: |
 
 - :white_check_mark: - fully tested, should works fine
 - :interrobang: - maybe works, not tested

tasks/install.debian.yml

@@ -15,22 +15,6 @@
     id: "{{ mongodb_apt_key_id[mongodb_major_version] }}"
   when: mongodb_package == 'mongodb-org'
 
-- name: Fail when used wrong mongodb_version variable with Debian Stretch
-  fail:
-    msg: "mongodb_version variable should be '3.6' or '4.0' or '4.2' for Debian Stretch"
-  when:
-    - mongodb_package == 'mongodb-org'
-    - (mongodb_major_version != '3.6' and mongodb_major_version != '4.0' and mongodb_major_version != '4.2')
-    - ansible_distribution_release == 'stretch'
-
-- name: Fail when used wrong mongodb_version variable with Ubuntu 18.04
-  fail:
-    msg: "mongodb_version variable should be '4.0' or '4.2', or else mongodb_package should be 'mongodb' for Ubuntu 18.04"
-  when:
-    - mongodb_package == 'mongodb-org'
-    - (mongodb_major_version != '4.0' and mongodb_major_version != '4.2')
-    - ansible_distribution_release == "bionic"
-
 - name: Fail when used wrong mongodb_version variable
   fail:
     msg: "mongodb_version variable should be '3.6' or '4.0' or '4.2'"