Merge pull request #318 from NigelWu95/ok3.11-im

add MultipartBody and Headers and use okhttp3.11.0 implements in http…

Author: longbai

.gitignore

@@ -30,4 +30,4 @@ build/
 # Android Studio
 .idea/workspace.xml
 .idea/libraries
-
+.idea/kotlinc.xml

.idea/caches/build_file_checksums.ser

@@ -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

.idea/codeStyles/Project.xml

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<module external.linked.project.id="android-sdk" external.linked.project.path="$MODULE_DIR$" external.root.project.path="$MODULE_DIR$" external.system.id="GRADLE" external.system.module.group="" external.system.module.version="unspecified" type="JAVA_MODULE" version="4">
+<module external.linked.project.id="android-sdk" external.linked.project.path="$MODULE_DIR$" external.root.project.path="$MODULE_DIR$" external.system.id="GRADLE" type="JAVA_MODULE" version="4">
   <component name="FacetManager">
     <facet type="java-gradle" name="Java-Gradle">
       <configuration>