Update Travis file for supported PHP versions, allowed failures.

https://docs.moodle.org/39/en/PHP#PHP_Versions

Author: jwcatau

.travis.yml

@@ -19,6 +19,7 @@ services:
   - postgresql
 
 matrix:
+  fast_finish: true
   include:
     - php: 7.0
       env: DB=mysqli MOODLE_BRANCH=MOODLE_35_STABLE
@@ -36,14 +37,6 @@ matrix:
       env: DB=mysqli MOODLE_BRANCH=MOODLE_38_STABLE
     - php: 7.1
       env: DB=pgsql  MOODLE_BRANCH=MOODLE_38_STABLE
-    - php: 7.1
-      env: DB=mysqli MOODLE_BRANCH=MOODLE_39_STABLE
-    - php: 7.1
-      env: DB=pgsql  MOODLE_BRANCH=MOODLE_39_STABLE
-    - php: 7.1
-      env: DB=mysqli MOODLE_BRANCH=master
-    - php: 7.1
-      env: DB=pgsql  MOODLE_BRANCH=master
     - php: 7.2
       env: DB=mysqli MOODLE_BRANCH=MOODLE_35_STABLE
     - php: 7.2
@@ -68,10 +61,6 @@ matrix:
       env: DB=pgsql  MOODLE_BRANCH=master
     - php: 7.2
       env: DB=mysqli MOODLE_BRANCH=master
-    - php: 7.3
-      env: DB=mysqli MOODLE_BRANCH=MOODLE_35_STABLE
-    - php: 7.3
-      env: DB=pgsql  MOODLE_BRANCH=MOODLE_35_STABLE
     - php: 7.3
       env: DB=pgsql  MOODLE_BRANCH=MOODLE_37_STABLE
     - php: 7.3
@@ -88,14 +77,6 @@ matrix:
       env: DB=pgsql  MOODLE_BRANCH=master
     - php: 7.3
       env: DB=mysqli MOODLE_BRANCH=master
-    - php: 7.4
-      env: DB=mysqli MOODLE_BRANCH=MOODLE_35_STABLE
-    - php: 7.4
-      env: DB=pgsql  MOODLE_BRANCH=MOODLE_35_STABLE
-    - php: 7.4
-      env: DB=pgsql  MOODLE_BRANCH=MOODLE_37_STABLE
-    - php: 7.4
-      env: DB=mysqli MOODLE_BRANCH=MOODLE_37_STABLE
     - php: 7.4
       env: DB=mysqli MOODLE_BRANCH=MOODLE_38_STABLE
     - php: 7.4
@@ -108,6 +89,16 @@ matrix:
       env: DB=pgsql  MOODLE_BRANCH=master
     - php: 7.4
       env: DB=mysqli MOODLE_BRANCH=master
+  allow_failures:
+    # Prevent Travis CI build faiures due to deprecated PHP warnings
+    - php: 7.4
+      env: DB=mysqli MOODLE_BRANCH=MOODLE_35_STABLE
+    - php: 7.4
+      env: DB=pgsql  MOODLE_BRANCH=MOODLE_35_STABLE
+    - php: 7.4
+      env: DB=mysqli MOODLE_BRANCH=MOODLE_37_STABLE
+    - php: 7.4
+      env: DB=pgsql  MOODLE_BRANCH=MOODLE_37_STABLE
 
 
 before_install: