Cleanup of gradle configuration and updating dependencies

build.gradle

@@ -5,13 +5,14 @@ buildscript {
         google()
         jcenter()
     }
+
     dependencies {
         classpath 'com.android.tools.build:gradle:3.1.4'
 
         // NOTE: Do not place your application dependencies here; they belong
         // in the individual module build.gradle files
 
-        classpath 'com.jfrog.bintray.gradle:gradle-bintray-plugin:1.4'
+        classpath 'com.jfrog.bintray.gradle:gradle-bintray-plugin:1.7.3'
         classpath 'com.github.dcendents:android-maven-gradle-plugin:1.4.1'
     }
 }
@@ -23,6 +24,14 @@ allprojects {
     }
 }
 
+ext {
+    compileSdkVersion = 27
+    buildToolsVersion = "27.0.3"
+    supportLibVersion = "27.1.1"
+    junitVersion = "4.12"
+    mockitoVersion = "2.18.3"
+}
+
 
 task clean(type: Delete) {
     delete rootProject.buildDir

sample/build.gradle

@@ -1,16 +1,17 @@
 apply plugin: 'com.android.application'
 
 android {
-    compileSdkVersion 27
-    buildToolsVersion "27.0.3"
+    compileSdkVersion rootProject.ext.compileSdkVersion
+    buildToolsVersion rootProject.ext.buildToolsVersion
+
     defaultConfig {
         applicationId "com.techyourchance.threadposters"
         minSdkVersion 16
-        targetSdkVersion 27
+        targetSdkVersion 28
         versionCode 1
         versionName "1.0"
-        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
     }
+
     buildTypes {
         release {
             minifyEnabled false
@@ -23,8 +24,8 @@ dependencies {
     implementation project(path: ':threadposter')
     implementation fileTree(dir: 'libs', include: ['*.jar'])
 
-    implementation 'com.android.support:appcompat-v7:27.1.1'
+    implementation "com.android.support:appcompat-v7:${rootProject.ext.supportLibVersion}"
 
-    testImplementation 'junit:junit:4.12'
-    testImplementation "org.mockito:mockito-core:2.12.0"
+    testImplementation "junit:junit:${rootProject.ext.junitVersion}"
+    testImplementation "org.mockito:mockito-core:${rootProject.ext.mockitoVersion}"
 }

threadposter/build.gradle

@@ -29,12 +29,12 @@ ext {
 }
 
 android {
-    compileSdkVersion 27
+    compileSdkVersion rootProject.ext.compileSdkVersion
     buildToolsVersion "27.0.3"
 
     defaultConfig {
         minSdkVersion 16
-        targetSdkVersion 27
+        targetSdkVersion 28
         versionCode 2
         versionName "0.8.0"
     }
@@ -48,12 +48,13 @@ android {
 
 dependencies {
     implementation fileTree(dir: 'libs', include: ['*.jar'])
-    testImplementation 'junit:junit:4.12'
-    testImplementation "org.mockito:mockito-core:2.12.0"
+    testImplementation "junit:junit:${rootProject.ext.junitVersion}"
+    testImplementation "org.mockito:mockito-core:${rootProject.ext.mockitoVersion}"
 }
 
-//Add these lines to publish library to bintray. This is the readymade scripts made by github user nuuneoi to make uploading to bintray easy.
-//Place it at the end of the file
+// Add these lines to publish library to bintray.
+// This is the readymade scripts made by github user nuuneoi to make uploading to bintray easy.
+// Place it at the end of the file
 if (project.rootProject.file('local.properties').exists()) {
     apply from: 'https://raw.githubusercontent.com/nuuneoi/JCenter/master/installv1.gradle'
     apply from: 'https://raw.githubusercontent.com/nuuneoi/JCenter/master/bintrayv1.gradle'