Update link to build status

This updates the link to the build status

README.md

@@ -1,6 +1,6 @@
 # Modelica Buildings library
 
-[![Build Status](https://travis-ci.com/lbl-srg/modelica-buildings.svg?branch=master)](https://travis-ci.com/lbl-srg/modelica-buildings)
+[![Build Status](https://app.travis-ci.com/lbl-srg/modelica-buildings.svg?branch=master)](https://app.travis-ci.com/lbl-srg/modelica-buildings)
 
 This is the development site for the Modelica _Buildings_ library and its user guide.
 
@@ -115,4 +115,4 @@ _Journal of Building Performance Simulation_, 7(4):253-270, 2014.
   url     = "https://doi.org/10.1080/19401493.2013.765506"
 }
 
-```
+```