remove uneeded requirements

requirements.txt

 numpy
-recursivenodes
 git+https://github.com/inducer/pytools.git#egg=pytools
-git+https://github.com/inducer/gmsh_interop.git#egg=gmsh_interop
-git+https://github.com/inducer/pyvisfile.git#egg=pyvisfile
-git+https://github.com/inducer/modepy.git#egg=modepy
+git+https://github.com/inducer/pymbolic.git#egg=pymbolic
+
 git+https://github.com/inducer/pyopencl.git#egg=pyopencl
 git+https://github.com/inducer/islpy.git#egg=islpy
 
-# required by pytential, which is in turn needed for some tests
-git+https://github.com/inducer/pymbolic.git#egg=pymbolic
-
-# also depends on pymbolic, so should come after it
 git+https://github.com/inducer/loopy.git#egg=loopy
-
-# requires pymetis for tests for partition_mesh
 git+https://github.com/inducer/pytato.git#egg=pytato