Using sass ie-hex-str for colors in IE filters

This fixes blue buttons (#1252) issue in IE, tested in IE9.
Make sure assets are precompiled on Heroku

Heroku recommends that `config.assets.initialize_on_precompile = false`,
which means that this initializer will not be invoked by
`rake assets:precompile`, which forces developers deploying to Heroku
to duplicate this initializer in their apps' configs.
Merge pull request #1904 from nbartlomiej/bugfix/1252-blue-buttons

Using sass ie-hex-str for colors in IE filters. Closes #1252
Merge pull request #1910 from exviva/always_configure_precompile

Make sure assets are precompiled on Heroku
add pagination and filters config
Merge pull request #1985 from rdsoze/update_install_template

add pagination and filters config
get Travis CI working

## Changes

### Misc
- reordered Gemfile -- shouldn't change functionality
- fix test env builder to support Rails versions properly

### Issues
- #1966
  - fix missing `decorator_method` for Draper
- #1967
  - remove 1.9 hash syntax
  - fix I18n dynamic re-translation feature

### Travis
- use latest Rails maintainence releases
- use latest Bundler version
- remove REE & 1.9.2
- add 2.0.0
Revert "Merge pull request #1961 from howaboutwe/1960_pluralize_generated_admin_user"

This reverts commit 02851874a0374115964ad3f8c252854bfc005e8d, reversing
changes made to 3e685688c9787ea01b8e1ad940a0d7326837356f.
Merge pull request #1970 from Daxter/bugfix/1927-travis-ci

[1927] Get Travis CI working