Composer no longer requires GitHub tokens.

See composer/composer#4884 (comment)

.travis.yml

@@ -1,27 +1,25 @@
 language: php
 
 matrix:
-    include:
-        - php: 7.0
-        - php: 7.1
-        - php: 7.2
-        - php: nightly
-    fast_finish: true
-    allow_failures:
-        - php: nightly
+  include:
+    - php: 7.0
+    - php: 7.1
+    - php: 7.2
+    - php: nightly
+  fast_finish: true
+  allow_failures:
+    - php: nightly
 
-before_install:
-    - phpenv config-rm xdebug.ini || true
-    - 'if [[ $GITHUB_TOKEN ]]; then echo "Configuring Composer GitHub token..."; composer config --global github-oauth.github.com "$GITHUB_TOKEN"; else echo "GitHub token unavailable."; fi'
+before_install: phpenv config-rm xdebug.ini || true
 install: composer install --prefer-dist --no-progress --no-interaction
 script: make test
 
 env:
-    global:
-        - secure: "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"
+  global:
+    - secure: "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"
 
 cache:
-    directories:
-        - $HOME/.composer/cache/files
+  directories:
+    - $HOME/.composer/cache/files
 
 sudo: false