Abstract away service name (#268)

* Abstract away service name

Signed-off-by: Harsha Vamsi Kalluri <harshavamsi096@gmail.com>

* Compuute x-amz-content-256 header

Signed-off-by: Harsha Vamsi Kalluri <harshavamsi096@gmail.com>

* Fix async signing

Signed-off-by: Harsha Vamsi Kalluri <harshavamsi096@gmail.com>

* Adds types-six to dependencies

Signed-off-by: Harsha Vamsi Kalluri <harshavamsi096@gmail.com>

* Optionally remove Content-Length

Signed-off-by: Harsha Vamsi Kalluri <harshavamsi096@gmail.com>

* Fix dict typo

Signed-off-by: Harsha Vamsi Kalluri <harshavamsi096@gmail.com>

* Remove requirement for x-amz-content-sha256 header

Signed-off-by: Harsha Vamsi Kalluri <harshavamsi096@gmail.com>

* Remove deletion of content-length

Signed-off-by: Harsha Vamsi Kalluri <harshavamsi096@gmail.com>

* Fix capitalization

Signed-off-by: Harsha Vamsi Kalluri <harshavamsi096@gmail.com>

* Adding unit tests

Signed-off-by: Harsha Vamsi Kalluri <harshavamsi096@gmail.com>

Signed-off-by: Harsha Vamsi Kalluri <harshavamsi096@gmail.com>

docs/source/conf.py

@@ -17,9 +17,9 @@
 
 # -- Project information -----------------------------------------------------
 
-project = 'OpenSearch Python Client'
-copyright = 'OpenSearch Project Contributors'
-author = 'OpenSearch Project Contributors'
+project = "OpenSearch Python Client"
+copyright = "OpenSearch Project Contributors"
+author = "OpenSearch Project Contributors"
 
 
 # -- General configuration ---------------------------------------------------
@@ -38,7 +38,7 @@ extensions = [
 ]
 
 # Add any paths that contain templates here, relative to this directory.
-templates_path = ['_templates']
+templates_path = ["_templates"]
 
 # List of patterns, relative to source directory, that match files and
 # directories to ignore when looking for source files.
@@ -51,12 +51,12 @@ exclude_patterns = []
 # The theme to use for HTML and HTML Help pages.  See the documentation for
 # a list of builtin themes.
 #
-html_theme = 'sphinx_rtd_theme'
+html_theme = "sphinx_rtd_theme"
 
 # Add any paths that contain custom static files (such as style sheets) here,
 # relative to this directory. They are copied after the builtin static files,
 # so a file named "default.css" will overwrite the builtin "default.css".
-html_static_path = ['_static']
+html_static_path = ["_static"]
 
 # -- additional settings -------------------------------------------------
 intersphinx_mapping = {