Modify the method on how ComponenetType is determined

The old code worked for Gradle modules, but with the RulerCli and the possibility to pass componenets that are build with other build systems this is no longer correct

ruler-common/src/main/java/com/spotify/ruler/common/dependency/DependencySanitizer.kt

@@ -58,9 +58,14 @@ class DependencySanitizer(private val classNameSanitizer: ClassNameSanitizer) {
         }
     }
 
-    /** Determines the correct component type for a given [entry]. */
+    private val versionRegex = Regex("^\\d+\\.\\d+\\.\\d.*")
+
+    /**
+     * Determines the correct component type for a given [entry].
+     * Assuming that all external dependencies do have a version number in the format XX.XX.XX
+     * */
     private fun getComponentType(entry: DependencyEntry): ComponentType = when {
-        entry.component.startsWith(':') -> ComponentType.INTERNAL
-        else -> ComponentType.EXTERNAL
+        versionRegex.containsMatchIn(entry.component.substringAfterLast(":","")) -> ComponentType.EXTERNAL
+        else -> ComponentType.INTERNAL
     }
 }