Allow Nextcloud 21 and adjust CI matrix

Signed-off-by: Christoph Wurst <christoph@winzerhof-wurst.at>

.travis.yml

@@ -2,7 +2,6 @@ sudo: required
 dist: xenial
 language: php
 php:
-  - 7.2
   - 7.3
   - 7.4
 
@@ -28,16 +27,18 @@ env:
 
 matrix:
   include:
-    - php: 7.2
+    - php: 7.3
       env: "DB=mysql PHP_COVERAGE=TRUE"
-    - php: 7.2
+    - php: 7.4
       env: "DB=mysql TEST_JS=TRUE"
-    - php: 7.3
+    - php: 7.4
       env: "DB=pgsql"
-    - php: 7.3
+    - php: 7.2
       env: "CORE_BRANCH=stable18"
     - php: 7.3
       env: "CORE_BRANCH=stable19"
+    - php: 7.4
+      env: "CORE_BRANCH=stable20"
     - php: nightly
       env: "PATCH_VERSION_CHECK=TRUE"
   fast_finish: true

appinfo/info.xml

@@ -21,7 +21,7 @@
 		<database>sqlite</database>
 		<database>mysql</database>
 		<database>pgsql</database>
-		<nextcloud min-version="18" max-version="20" />
+		<nextcloud min-version="18" max-version="21" />
 	</dependencies>
 
 	<two-factor-providers>