added badge for https://lgtm.com and cleaned up warnings

1 files changed, 2 insertions, 1 deletions

diff --git a/README.md b/README.md
index 66ec41af..89c4c32d 100644
--- a/README.md
+++ b/README.md
@@ -78,11 +78,12 @@ The framework can be used like any other if you don't want/need to mix productio
 
 [This table](https://github.com/martinmoene/catch-lest-other-comparison) compares **doctest** / [**Catch**](https://github.com/philsquared/Catch) / [**lest**](https://github.com/martinmoene/lest) which are all very similar.
 
-[![Standard](https://img.shields.io/badge/c%2B%2B-11/14/17-blue.svg)](https://en.wikipedia.org/wiki/C%2B%2B#Standardization)
+[![Standard](https://img.shields.io/badge/c%2B%2B-11/14/17/20-blue.svg)](https://en.wikipedia.org/wiki/C%2B%2B#Standardization)
 [![License](https://img.shields.io/badge/license-MIT-blue.svg)](https://opensource.org/licenses/MIT)
 [![Version](https://badge.fury.io/gh/onqtam%2Fdoctest.svg)](https://github.com/onqtam/doctest/releases)
 [![download](https://img.shields.io/badge/download%20%20-latest-blue.svg)](https://raw.githubusercontent.com/onqtam/doctest/master/doctest/doctest.h)
 [![CII Best Practices](https://bestpractices.coreinfrastructure.org/projects/503/badge)](https://bestpractices.coreinfrastructure.org/projects/503)
+[![Language grade: C/C++](https://img.shields.io/lgtm/grade/cpp/g/onqtam/doctest.svg?logo=lgtm&logoWidth=18)](https://lgtm.com/projects/g/onqtam/doctest/context:cpp)
 [![Join the chat at https://gitter.im/onqtam/doctest](https://badges.gitter.im/onqtam/doctest.svg)](https://gitter.im/onqtam/doctest?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
 [![Try it online](https://img.shields.io/badge/try%20it-online-orange.svg)](https://wandbox.org/permlink/nRXesFZUIjiLBQa6)
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