Update .travis.yml

Specifying all of the dependencies in `REQUIRE` and `.travis.yml` is silly / error prone. Let's let `Pkg.clone` do that
remove .git/shallow
fix for warnings generated by shallow clone in travis
Merge pull request #420 from WestleyArgentum/patch-1

Update .travis.yml
Fix #419, FS.rename warning
handle non-shallow clones

For local clones and clones by travis of repos with less than 50 commits `git fetch --unshallow` was throwing a fatal error.

Also, it's probably a little cleaner to do repo manipulation stuff in the `before_install` section.
Allow ddataframe test to be run from any directory
Merge pull request #421 from WestleyArgentum/patch-2

handle non-shallow clones
Relaxed handling of newlines.
Merge pull request #423 from dcjones/master

Relaxed handling of newlines.
Strip column names before clean_colnames!

Strip column names before clean_colnames! to remove whitespace before replacing invalid characters with '_'.
Use .travis.yml based on Pkg default for new packages

`git fetch --unshallow` looks like it's throwing errors
(https://travis-ci.org/JuliaStats/DataFrames.jl/builds/14701699)
Revert "Use .travis.yml based on Pkg default for new packages"

This reverts commit 09d4b3f8aad81883b467017638960368fbc12997.
Update git before trying to unshallow
Updates to sorting interface to better match mainline julia

* Allow user to specify sort order by keyword/column tuple or array
  (e.g., rev=(true,false,false)
* Allow user to specify sort order by order(...) function
  (e.g., order("colname", rev=true) )
* Added issorted(...), and accept the same kw arguments
* Added tests
* Added docs
Merge pull request #389 from kmsquire/sorting_update

DataFrame sorting update
Merge pull request #422 from simonster/fs

Fix #419, FS.rename warning
Fix some errors relating to vector() and matrix()
Catch up with DataArrays
Shut off colfuncs tests