starlette instrumentation (#777)

adding an initial starlette instrumentation.

tox does exact match on fields delimited by a dash. Thus,
any instrumentation that includes "instrumentation" in the name
would collide with testing of the "opentelemetry-instrumentation"
package.

Renaming opentelemetry-instrumentation to opentelemetry-instrumentation-base to fix that.

Co-authored-by: Leighton Chen <lechen@microsoft.com>
Co-authored-by: alrex <aboten@lightstep.com>

scripts/check_for_valid_readme.py

@@ -10,7 +10,7 @@ def is_valid_rst(path):
     """Checks if RST can be rendered on PyPI."""
     with open(path) as readme_file:
         markup = readme_file.read()
-    return readme_renderer.rst.render(markup) is not None
+    return readme_renderer.rst.render(markup, stream=sys.stderr) is not None
 
 
 def parse_args():