Fix header casting and more minor fixes

Author: eldadfux

appwrite.gemspec

@@ -1,7 +1,7 @@
 Gem::Specification.new do |s|
 
   s.name = 'appwrite'
-  s.version = '2.1.0'
+  s.version = '2.1.1'
   s.summary = "Appwrite is an open-source self-hosted backend server that abstract and simplify complex and repetitive development tasks behind a very simple REST API"
   s.author = 'Appwrite Team'
   s.homepage = 'https://appwrite.io/support'

docs/examples/functions/create-tag.md

@@ -10,6 +10,6 @@ client
 
 functions = Appwrite::Functions.new(client);
 
-response = functions.create_tag(function_id: '[FUNCTION_ID]', command: '[COMMAND]', code: Appwrite::File.new());
+response = functions.create_tag(function_id: '[FUNCTION_ID]', command: '[COMMAND]', code: '');
 
 puts response

docs/examples/storage/create-file.md

@@ -10,6 +10,6 @@ client
 
 storage = Appwrite::Storage.new(client);
 
-response = storage.create_file(file: Appwrite::File.new());
+response = storage.create_file(file: '');
 
 puts response

lib/appwrite/client.rb

@@ -20,7 +20,7 @@ def initialize()
             @headers = {
                 'content-type' => '',
                 'user-agent' => RUBY_PLATFORM + ':ruby-' + RUBY_VERSION,
-                'x-sdk-version' => 'appwrite:ruby:2.1.0',                
+                'x-sdk-version' => 'appwrite:ruby:2.1.1',                
                 'X-Appwrite-Response-Format' => '0.8.0'
             }
             @endpoint = 'https://appwrite.io/v1';
@@ -57,7 +57,7 @@ def set_endpoint(endpoint)
         end
 
         def add_header(key, value)
-            @headers[key.downcase] = value.downcase
+            @headers[key.downcase] = value
 
             return self
         end