tests: Makefile.am: Add missing tests client keys in distribution tarball (#604)
tests: Makefile.am: Add missing tests client keys in distribution tarball (#604)

Notes:
Added missing test keys.

Credit:
Laurent Stacul
libssh2/libssh2,libssh2/libssh2,libssh2/libssh2,libssh2/libssh2