Build Phar on 7.1 so it doesn’t get php73 polyfill

Fixes #1739

.travis.yml

@@ -49,9 +49,6 @@ matrix:
   fast_finish: true
   allow_failures:
     - php: nightly
-  exclude: # covered in Code coverage stage
-    - php: 7.3
-      env: DEPS="high"
 
 # Additional stages
 jobs:
@@ -63,7 +60,7 @@ jobs:
         - vendor/bin/phpcs
 
     - stage: Phar build
-      php: 7.3
+      php: 7.1
       env: DEPS="high"
       script: bin/build-phar.sh
       deploy:

composer.json

@@ -20,7 +20,7 @@
         "netresearch/jsonmapper": "^1.0",
         "webmozart/glob": "^4.1",
         "webmozart/path-util": "^2.3",
-        "symfony/console": "^3.3||4.0.*||4.1.*||4.2.*",
+        "symfony/console": "^3.3||^4.0",
         "amphp/amp": "^2.1",
         "amphp/byte-stream": "^1.5",
         "sebastian/diff": "^3.0"