update shields to master

Signed-off-by: Kale Franz <[email protected]>

README.rst

@@ -7,17 +7,17 @@
 
 ----------------------------------------
 
-.. image:: https://img.shields.io/circleci/project/github/conda/conda/4.4.x.svg?maxAge=900&label=Unix
-    :target: https://circleci.com/gh/conda/workflows/conda/tree/4.4.x
+.. image:: https://img.shields.io/circleci/project/github/conda/conda/master.svg?maxAge=900&label=Unix
+    :target: https://circleci.com/gh/conda/workflows/conda/tree/master
     :alt: Unix tests (CircleCI)
 
-.. image:: https://img.shields.io/appveyor/ci/ContinuumAnalyticsFOSS/conda/4.4.x.svg?maxAge=900&label=Windows
+.. image:: https://img.shields.io/appveyor/ci/ContinuumAnalyticsFOSS/conda/master.svg?maxAge=900&label=Windows
     :target: https://ci.appveyor.com/project/ContinuumAnalyticsFOSS/conda
     :alt: Windows tests (Appveyor)
 
-.. image:: https://img.shields.io/codecov/c/github/conda/conda/4.4.x.svg?label=coverage
+.. image:: https://img.shields.io/codecov/c/github/conda/conda/master.svg?label=coverage
    :alt: Codecov Status
-   :target: https://codecov.io/gh/conda/conda/branch/4.4.x
+   :target: https://codecov.io/gh/conda/conda/branch/master
 
 .. image:: https://img.shields.io/github/release/conda/conda.svg
    :alt: latest release version