Remove fping requirement

The os-fping API was deprecated in nova in
I92064cbcb5f6414da0c9d294f912a860428af698.  I can't see anything
obviously using it on codesearch.

This is only in EPEL for centos, which I'm trying to remove.  But I
think less dependencies is always better than more in general hence
the removal.

This is essentially a revert of
Ibdc7479a9038321e4fc3953774a6f3e1dac90530

Change-Id: I163fc48c860bae2a92c83cfdaed26b2e54630e20
diff --git a/files/debs/n-api b/files/debs/n-api
deleted file mode 100644
index 0928cd5..0000000
--- a/files/debs/n-api
+++ /dev/null
@@ -1 +0,0 @@
-fping
diff --git a/files/rpms-suse/n-api b/files/rpms-suse/n-api
index af5ac2f..0f08daa 100644
--- a/files/rpms-suse/n-api
+++ b/files/rpms-suse/n-api
@@ -1,2 +1 @@
-fping
 python-dateutil
diff --git a/files/rpms/n-api b/files/rpms/n-api
deleted file mode 100644
index 0928cd5..0000000
--- a/files/rpms/n-api
+++ /dev/null
@@ -1 +0,0 @@
-fping