Add extra version of py-pip (#15061)

var/spack/repos/builtin/packages/py-pip/package.py

@@ -13,6 +13,7 @@ class PyPip(PythonPackage):
     url      = "https://pypi.io/packages/source/p/pip/pip-19.3.tar.gz"
 
     version('19.3',   sha256='324d234b8f6124846b4e390df255cacbe09ce22791c3b714aa1ea6e44a4f2861')
+    version('19.1.1', sha256='44d3d7d3d30a1eb65c7e5ff1173cdf8f7467850605ac7cc3707b6064bddd0958')
     version('19.0.3', sha256='6e6f197a1abfb45118dbb878b5c859a0edbdd33fd250100bc015b67fded4b9f2')
     version('18.1',   sha256='c0a292bd977ef590379a3f05d7b7f65135487b67470f6281289a94e015650ea1')
     version('10.0.1', sha256='f2bd08e0cd1b06e10218feaf6fef299f473ba706582eb3bd9d52203fdbd7ee68')