minor changes

app/src/main/res/values/colors.xml

@@ -49,5 +49,4 @@
 
     <!-- Default Background Color -->
     <color name="default_background">#FAFAFA</color>
-
 </resources>

draw/build.gradle

 apply plugin: 'com.android.library'
 
 android {
-    compileSdkVersion 27
+    compileSdkVersion versions.compileSdk
+    buildToolsVersion versions.buildTools
 
     defaultConfig {
         minSdkVersion 21
-        targetSdkVersion 27
+        targetSdkVersion versions.targetSdk
         versionCode 1
         versionName "1.0"
-
         testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
-
     }
 
     buildTypes {