Take "" and "/" as equivalent namespaces on server

On server, `.of(name)` should use the same key in `.nsps` object for "" and "/"

Important to use `String(name)` and `===` to keep out keys that don't cast to ""
Added relevant tests

"" and "/" namespaces are checked for equivalence on server and client
Update index.js
testing for equivalence of namespaces starting with / or without
Merge pull request #1729 from anupbishnoi/patch-1

Take "" and "/" as equivalent namespaces on server
package: bump engine.io
examples: minor fix of escaping
Release 1.1.0
package: fix main file for example application 'chat'.
Merge pull request #1766 from BrianGeppert/master

package: fix main file for example application 'chat'.
Change "there're" to "there are"

Not a commonly used contraction and looks a bit odd.
Merge pull request #1784 from matthewcanty/patch-1

Change "there're" to "there are"
Add test to check that empty rooms are autopruned.
Bump adapter version.