LDAP Public SSH Keys synchronization (#1844)

* Add LDAP Key Synchronization feature

Signed-off-by: Magnus Lindvall <magnus@dnmgns.com>

* Add migration: add login source id column for public_key table

* Only update keys if needed

* Add function to only list pubkey synchronized from ldap

* Only list pub ssh keys synchronized from ldap. Do not sort strings as ExistsInSlice does it.

* Only get keys belonging to current login source id

* Set default login source id to 0

* Some minor cleanup. Add integration tests (updete dep testify)

vendor/github.com/davecgh/go-spew/spew/bypass.go

@@ -41,9 +41,9 @@ var (
 	// after commit 82f48826c6c7 which changed the format again to mirror
 	// the original format.  Code in the init function updates these offsets
 	// as necessary.
-	offsetPtr    = ptrSize
+	offsetPtr    = uintptr(ptrSize)
 	offsetScalar = uintptr(0)
-	offsetFlag   = ptrSize * 2
+	offsetFlag   = uintptr(ptrSize * 2)
 
 	// flagKindWidth and flagKindShift indicate various bits that the
 	// reflect package uses internally to track kind information.
@@ -58,7 +58,7 @@ var (
 	// changed their positions.  Code in the init function updates these
 	// flags as necessary.
 	flagKindWidth = uintptr(5)
-	flagKindShift = flagKindWidth - 1
+	flagKindShift = uintptr(flagKindWidth - 1)
 	flagRO        = uintptr(1 << 0)
 	flagIndir     = uintptr(1 << 1)
 )