added drone ci

* updated gradle wrapper to gradle 5.6.2

.drone.yml

@@ -0,0 +1,9 @@
+kind: pipeline
+name: default
+
+steps:
+- name: assembleRelease
+  image: gradle:jdk8
+  commands:
+  - gradle assembleRelease
+ 

gradle/wrapper/gradle-wrapper.properties

@@ -1,5 +1,5 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-5.5.1-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-5.6.2-bin.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists

gradlew

@@ -7,7 +7,7 @@
 # you may not use this file except in compliance with the License.
 # You may obtain a copy of the License at
 #
-#      http://www.apache.org/licenses/LICENSE-2.0
+#      https://www.apache.org/licenses/LICENSE-2.0
 #
 # Unless required by applicable law or agreed to in writing, software
 # distributed under the License is distributed on an "AS IS" BASIS,

gradlew.bat

@@ -5,7 +5,7 @@
 @rem you may not use this file except in compliance with the License.
 @rem You may obtain a copy of the License at
 @rem
-@rem      http://www.apache.org/licenses/LICENSE-2.0
+@rem      https://www.apache.org/licenses/LICENSE-2.0
 @rem
 @rem Unless required by applicable law or agreed to in writing, software
 @rem distributed under the License is distributed on an "AS IS" BASIS,