Issue #3093410: Update the default travis-ci PHP testing version from PHP7.2...

Issue #3093410: Update the default travis-ci PHP testing version from PHP7.2 to PHP7.3 for Automated Functional Acceptance Testing groups

.travis.yml

@@ -10,7 +10,7 @@ cache:
     - "$HOME/.selenium/cache"
 
 php:
-  - 7.2
+  - 7.3
 
 env:
   - AFATG=01-website-base-requirements
@@ -22,23 +22,23 @@ env:
 matrix:
   exclude:
 # Automated Functional Acceptance Testing group: 01 website base requirements
-  - php: 7.2
+  - php: 7.3
     env: AFATG=01-website-base-requirements
 
 # Automated Functional Acceptance Testing group: 02 user management
-  - php: 7.2
+  - php: 7.3
     env: AFATG=02-user-management
 
 # Automated Functional Acceptance Testing group: 03 admin management
-  - php: 7.2
+  - php: 7.3
     env: AFATG=03-admin-management
 
 # Automated Functional Acceptance Testing group: 04 content structure
-  - php: 7.2
+  - php: 7.3
     env: AFATG=04-content-structure
 
 # Automated Functional Acceptance Testing group: 05 content-management
-  - php: 7.2
+  - php: 7.3
     env: AFATG=05-content-management
 
 mysql: