Updated build tools version and added gradle script for automatic sig…

…ning.

app/build.gradle

@@ -13,8 +13,22 @@ def gitSha() {
 }
 
 android {
+    def signingPropFile = new File(System.properties['user.home'], ".signing/reddit-android-appstore/signing.properties")
+    if (signingPropFile.canRead()) {
+        def Properties signingProps = new Properties()
+        signingProps.load(new FileInputStream(signingPropFile))
+        signingConfigs {
+            release {
+                storeFile new File(signingProps['release.storePath'])
+                keyAlias signingProps['release.keyAlias']
+                storePassword signingProps['release.storePassword']
+                keyPassword signingProps['release.keyPassword']
+            }
+        }
+    }
+
     compileSdkVersion 25
-    buildToolsVersion "25.0.2"
+    buildToolsVersion "25.0.3"
 
     def versionMajor = 0
     def versionMinor = 7
@@ -40,6 +54,7 @@ android {
             testProguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
         }
         release {
+            signingConfig signingConfigs.release
             minifyEnabled false
             useProguard false
             proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'