Scripts for podspec updation and github tag release

Summary:
This diff adds the support to automate iOS releases. This diff adds two scripts, one for updating all the `podspecs`, and `podfiles` with updated version number. The script also updates the version used in sample and getting started doc file.
The second script publishes a github tag.

Following will be the process for iOS release:-

1. From `fbobjc/Libraries/SonarKit/Scripts` run `sh public-ios-podspec-update.sh`, it will update all the podspecs, podfiles and docs with updated version number. Commit it and land this
2. Once the above changes are landed and synced to github, run `sh push-new-github-tag.sh` from `fbobjc/Libraries/SonarKit/Scripts` to push the tag on github

As a follow up on this diff, ideally, we should trigger second script automatically when the 1st task changes are synced to github.

Reviewed By: jknoxville

Differential Revision: D8879958

fbshipit-source-id: 8f0dc9200e8f64578af33e1446629f09c16c43f2

iOS/Sample/Podfile

@@ -3,11 +3,11 @@ source 'https://github.com/facebook/Sonar.git'
 source 'https://github.com/CocoaPods/Specs'
 # Uncomment the next line to define a global platform for your project
 swift_version = "4.1"
-
+sonarkit_version = '0.6.12'
 
 target 'Sample' do
 
-  pod 'SonarKit', '~>0.6'
+  pod 'SonarKit', '~>'+sonarkit_version
   post_install do |installer|
 
         installer.pods_project.targets.each do |target|

iOS/SonarKit.podspec

@@ -1,7 +1,7 @@
 folly_compiler_flags = '-DFB_SONARKIT_ENABLED=1 -DFOLLY_NO_CONFIG -DFOLLY_MOBILE=1 -DFOLLY_USE_LIBCPP=1 -DFOLLY_HAVE_LIBGFLAGS=0 -DFOLLY_HAVE_LIBJEMALLOC=0 -DFOLLY_HAVE_PREADV=0 -DFOLLY_HAVE_PWRITEV=0 -DFOLLY_HAVE_TFO=0 -DFOLLY_USE_SYMBOLIZER=0'
 yoga_version = '~> 1.9'
 yogakit_version = '~>1.8'
-
+sonarkit_version = '0.6.12'
 Pod::Spec.new do |spec|
   spec.name = 'SonarKit'
   spec.version = '0.6.12'
@@ -11,13 +11,13 @@ Pod::Spec.new do |spec|
   spec.authors = 'Facebook'
   spec.static_framework = true
   spec.source = { :git => 'https://github.com/facebook/Sonar.git',
-                  :tag=> "v0.6.12" }
+                  :tag=> "v"+sonarkit_version }
   spec.module_name = 'SonarKit'
   spec.platforms = { :ios => "8.4" }
 
   spec.subspec "Core" do |ss|
     ss.dependency 'Folly', '~>1.0'
-    ss.dependency 'Sonar', '~>0.6'
+    ss.dependency 'Sonar', '~>'+sonarkit_version
     ss.dependency 'CocoaAsyncSocket', '~> 7.6'
     ss.dependency 'PeerTalk', '~>0.0.2'
     ss.dependency 'OpenSSL-Static', '1.0.2.c1'