Merge pull request #164 from SherlockGougou/master

升级sdk版本为28，添加gitignore，解决jitpack编译失败

.gitignore

@@ -0,0 +1,243 @@
+
+# Created by https://www.gitignore.io/api/java,macos,android,androidstudio
+# Edit at https://www.gitignore.io/?templates=java,macos,android,androidstudio
+
+### Android ###
+# Built application files
+*.apk
+*.ap_
+*.aab
+
+# Files for the ART/Dalvik VM
+*.dex
+
+# Java class files
+*.class
+
+# Generated files
+bin/
+gen/
+out/
+
+# Gradle files
+.gradle/
+build/
+
+# Local configuration file (sdk path, etc)
+local.properties
+
+# Proguard folder generated by Eclipse
+proguard/
+
+# Log Files
+*.log
+
+# Android Studio Navigation editor temp files
+.navigation/
+
+# Android Studio captures folder
+captures/
+
+# IntelliJ
+*.iml
+.idea/*
+.idea/workspace.xml
+.idea/tasks.xml
+.idea/gradle.xml
+.idea/assetWizardSettings.xml
+.idea/dictionaries
+.idea/libraries
+.idea/caches
+# Android Studio 3 in .gitignore file.
+.idea/caches/build_file_checksums.ser
+.idea/modules.xml
+
+# Keystore files
+# Uncomment the following lines if you do not want to check your keystore files in.
+#*.jks
+#*.keystore
+
+# External native build folder generated in Android Studio 2.2 and later
+.externalNativeBuild
+
+# Google Services (e.g. APIs or Firebase)
+# google-services.json
+
+# Freeline
+freeline.py
+freeline/
+freeline_project_description.json
+
+# fastlane
+fastlane/report.xml
+fastlane/Preview.html
+fastlane/screenshots
+fastlane/test_output
+fastlane/readme.md
+
+# Version control
+vcs.xml
+
+# lint
+lint/intermediates/
+lint/generated/
+lint/outputs/
+lint/tmp/
+# lint/reports/
+
+### Android Patch ###
+gen-external-apklibs
+output.json
+
+### AndroidStudio ###
+# Covers files to be ignored for android development using Android Studio.
+
+# Built application files
+
+# Files for the ART/Dalvik VM
+
+# Java class files
+
+# Generated files
+
+# Gradle files
+.gradle
+
+# Signing files
+.signing/
+
+# Local configuration file (sdk path, etc)
+
+# Proguard folder generated by Eclipse
+
+# Log Files
+
+# Android Studio
+/*/build/
+/*/local.properties
+/*/out
+/*/*/build
+/*/*/production
+*.ipr
+*~
+*.swp
+
+# Android Patch
+
+# External native build folder generated in Android Studio 2.2 and later
+
+# NDK
+obj/
+
+# IntelliJ IDEA
+*.iws
+/out/
+
+# User-specific configurations
+.idea/caches/
+.idea/libraries/
+.idea/shelf/
+.idea/.name
+.idea/compiler.xml
+.idea/copyright/profiles_settings.xml
+.idea/encodings.xml
+.idea/misc.xml
+.idea/scopes/scope_settings.xml
+.idea/vcs.xml
+.idea/jsLibraryMappings.xml
+.idea/datasources.xml
+.idea/dataSources.ids
+.idea/sqlDataSources.xml
+.idea/dynamic.xml
+.idea/uiDesigner.xml
+
+# OS-specific files
+.DS_Store
+.DS_Store?
+._*
+.Spotlight-V100
+.Trashes
+ehthumbs.db
+Thumbs.db
+
+# Legacy Eclipse project files
+.classpath
+.project
+.cproject
+.settings/
+
+# Mobile Tools for Java (J2ME)
+.mtj.tmp/
+
+# Package Files #
+*.war
+*.ear
+
+# virtual machine crash logs (Reference: http://www.java.com/en/download/help/error_hotspot.xml)
+hs_err_pid*
+
+## Plugin-specific files:
+
+# mpeltonen/sbt-idea plugin
+.idea_modules/
+
+# JIRA plugin
+atlassian-ide-plugin.xml
+
+# Mongo Explorer plugin
+.idea/mongoSettings.xml
+
+# Crashlytics plugin (for Android Studio and IntelliJ)
+com_crashlytics_export_strings.xml
+crashlytics.properties
+crashlytics-build.properties
+fabric.properties
+
+### AndroidStudio Patch ###
+
+!/gradle/wrapper/gradle-wrapper.jar
+
+### Java ###
+# Compiled class file
+
+# Log file
+
+# BlueJ files
+*.ctxt
+
+# Mobile Tools for Java (J2ME)
+
+# Package Files #
+*.jar
+*.nar
+*.zip
+*.tar.gz
+*.rar
+
+# virtual machine crash logs, see http://www.java.com/en/download/help/error_hotspot.xml
+
+### macOS ###
+# General
+.AppleDouble
+.LSOverride
+
+# Icon must end with two \r
+Icon
+
+# Thumbnails
+
+# Files that might appear in the root of a volume
+.DocumentRevisions-V100
+.fseventsd
+.TemporaryItems
+.VolumeIcon.icns
+.com.apple.timemachine.donotpresent
+
+# Directories potentially created on remote AFP share
+.AppleDB
+.AppleDesktop
+Network Trash Folder
+Temporary Items
+.apdisk
+
+# End of https://www.gitignore.io/api/java,macos,android,androidstudio