Replace Travis with GitLab CI

.gitlab-ci.yml

+image: openjdk:8-jdk-slim
+
+stages:
+  - test
+  - deploy
+
+variables:
+  GRADLE_OPTIONS: --no-daemon --info --stacktrace --warning-mode=all
+
+cache:
+  paths:
+    - .gradle/wrapper
+    - .gradle/caches
+
+before_script:
+  - export GRADLE_USER_HOME=`pwd`/.gradle
+
+tests:
+  stage: test
+  script: ./gradlew ${GRADLE_OPTIONS} check
+
+tests:jdk-11:
+  extends: tests
+  image: openjdk:11-jdk-slim
+
+tests:jdk-14:
+  extends: tests
+  image: openjdk:14-jdk-slim
+
+publish:
+  stage: deploy
+  script:
+    - openssl aes-256-cbc -pass "env:ENCRYPTION_PASSWORD" -d -a -md md5 -in secring.gpg.enc -out secring.gpg
+    - openssl aes-256-cbc -pass "env:ENCRYPTION_PASSWORD" -d -a -md md5 -in pubring.gpg.enc -out pubring.gpg
+    - openssl aes-256-cbc -pass "env:ENCRYPTION_PASSWORD" -d -a -md md5 -in gradle.properties.enc -out gradle.properties
+    - ./gradlew ${GRADLE_OPTIONS} uploadArchives

.travis.yml

-language: java
-
-before_install:
-- openssl aes-256-cbc -pass pass:$ENCRYPTION_PASSWORD -in secring.gpg.enc -out secring.gpg -d
-- openssl aes-256-cbc -pass pass:$ENCRYPTION_PASSWORD -in pubring.gpg.enc -out pubring.gpg -d
-- openssl aes-256-cbc -pass pass:$ENCRYPTION_PASSWORD -in gradle.properties.enc -out gradle.properties -d
-
-script: ./gradlew uploadArchives
-
-env:
-  global:
-    secure: kFKnWpX4wkRGZ6gdP5Y7Nl/Gd5EZYYuJfv8qU2wfullMfLxeB/N1ANhUVqS+pP9oTbA52SHy7gzHTKxk4aeYBgPoiVx4RwRFV1wPYzv9SENNGsHrDdtSNRGM0OBpDkem6rX+OZ5FJ2GRCtX5ba3frclo11HUiAsYvAtoX8sk6lU=

gradle.properties.enc

-Salted__LnX$o HJ1zVI2(,IA};p^E{q m1Vb7P4Moj^(]lpߝ[|USղD02BOz;+1e#/3`wWO-6TR+InxB/lG>SNj&G!iSy+#4Xf}ꏥ1E*+sS
+U2FsdGVkX1+772WWsEs8y4Z+vdhQLZyW24cH/04lX8CxgZ4JycDLZWPBAc70ZGyT
\ No newline at end of file
+w1lgwUF18NmTGDpjwyDkUQmXdYUHYRGUCLTeNays57gOaxEVQQz0zm0kKAISdnNW
+9IgD8BI/lbftz7Y8dqxMUBxfcUTijzJfXz+uEK53jwBoxKYVznzzCCfwEv+1KMR9
+oypMpm9HRBMEZyDkPRPJ2DKOFhW6YCdcszCjTNKmeJkOwVjfyltC43WXzcrzYKR/
+S2pGjR+7mcBg9zq0yMI+1DgMWwmrAaLP9pKnyDqDgXK1yJIKKE80C4NkJN6XVhHc
+qjWQ8xnLXRorA7j0lkWAhw==