Add automatic version number

.travis.yml

@@ -8,10 +8,12 @@ script:
   - jdk_switcher use oraclejdk8
   - ./gradlew assemble
   - ./gradlew check
+  - ./gradlew build --scan -s
   - ./gradlew test
   - jdk_switcher use openjdk8
   - ./gradlew assemble
   - ./gradlew check
+  - ./gradlew build --scan -s
   - ./gradlew test
   - ./gradlew run
   - ./gradlew javadoc

build.gradle

@@ -7,7 +7,9 @@ jacoco {
     toolVersion = "0.8.1" //checked at http://www.eclemma.org/jacoco/
 }
 
-version = '1.0.0'
+if (!project.hasProperty('version') || version == "unspecified"){
+    version =  "git describe --dirty --abbrev --always --tags".execute().text.trim()
+}
 applicationName = "ImmutableComplex"
 mainClassName = "main.java.Main"