Stop integration tests for Emacs 23

 - at least until I am able to install Emacs 23 locally
 - maybe for good?
[magnars/dash.el#18] implementing -slice
Merge pull request #19 from Wilfred/master

-slice implementation
Add Wilfred Hughes to list of contributors.
Release 1.1.0
inhibit dev from being added to the load-path
Merge pull request #20 from tarsius/master

inhibit dev from being added to the load-path
Handle cons-cells properly in -flatten

Fixes #21
Added -last
Merge pull request #23 from Fuco1/last

Added -last
Less implementation specific docs for -mapcat

Fixes #24
Don't use the word collection when meaning list
Add -when-let and -if-let macros
Merge pull request #26 from shosti/when-if-let

Add -when-let and -if-let macros
Add Emanuel Evans to list of contributors
Add -insert-at (closes #27)
Merge pull request #28 from shosti/master

Add -insert-at
Update @shosti's list of contributions.
Typo
Fix -when-let and -if-let docstrings