Cherry-picking pull request #5 (ed2850a) and ab74a36

💥 enforce minimum shadow version _1.2.3_.

This library depends on the first compatible shadow version. The
developer can enforce newer versions by just depending on them. This
fix avoids to possibly break old builds and keeps included shadow
version without the need to `force` it.

build.gradle

@@ -29,13 +29,19 @@ repositories {
 group 'de.sebastianboegl.gradle.plugins'
 
 // no real semantic versioning (the MAJOR version number correspond to the MAJOR shadow plugin version number)
-version "${shadowVersion}.0.1"
+version "${majorShadowVersion}.0.1"
+
+def shadowVersions = [
+    '1': '1.2.3',
+    '2': '2.0.0'
+]
+def shadowVersion = shadowVersions[majorShadowVersion]
 
 dependencies {
     compile gradleApi()
     compile localGroovy()
-    compile(group: 'org.apache.logging.log4j', name: 'log4j-core', version: '2.+')
-    compile "com.github.jengelman.gradle.plugins:shadow:${shadowVersion}.+"
+    compile(group: 'org.apache.logging.log4j', name: 'log4j-core', version: '2.10.0')
+    compile "com.github.jengelman.gradle.plugins:shadow:${shadowVersion}"
 
     testCompile gradleTestKit()
     testCompile ('org.spockframework:spock-core:1.0-groovy-2.4') {

gradle.properties

@@ -1 +1 @@
-shadowVersion = 1
+majorShadowVersion = 1