update .travis.yml.

Author: gawen957

.travis.yml

@@ -16,7 +16,7 @@ android:
     - build-tools-26.0.0
 
     # The SDK version used to compile your project
-    - android-25
+    - android-26
     - android-22
 
     # Specify at least one system image

library/build.gradle

@@ -20,12 +20,12 @@ String version = versionName()
 int code = versionNameToCode(version)
 
 android {
-    compileSdkVersion 28
+    compileSdkVersion 26
     buildToolsVersion '25.0.2'
     defaultConfig {
         //applicationId "com.qiniu.android"
         minSdkVersion 9
-        targetSdkVersion 28
+        targetSdkVersion 26
         versionCode code
         versionName version
     }

library/library.iml

@@ -98,7 +98,7 @@
       <excludeFolder url="file://$MODULE_DIR$/build/test-results" />
       <excludeFolder url="file://$MODULE_DIR$/build/tmp" />
     </content>
-    <orderEntry type="jdk" jdkName="Android API 28 Platform" jdkType="Android SDK" />
+    <orderEntry type="jdk" jdkName="Android API 26 Platform" jdkType="Android SDK" />
     <orderEntry type="sourceFolder" forTests="false" />
     <orderEntry type="library" exported="" name="Gradle: com.google.code.findbugs:jsr305:3.0.2@jar" level="project" />
     <orderEntry type="library" exported="" name="Gradle: com.squareup.okio:okio:1.14.0@jar" level="project" />