Merge remote-tracking branch 'pr/237' into develop

Twitter Feature on Main-View from @loadtocode

Twitter feature within home/index of LEAP web app as feed of tweets of one user's twitter account

How to use it: set up an Application-only authentication by twitter (https://dev.twitter.com/oauth/application-only) and then create a config/secrets.yml including:
```
development:
  twitter:
    enabled: false # set to true for usage
    twitter_handle: XXXXX #put your twitter handle here
    bearer_token: XXXXX #put your bearer token here
test:
  twitter:
    enabled: false # set to true for usage
    twitter_handle: XXXXX #put your twitter handle here
    bearer_token: XXXXX #put your bearer token here
```

things in the PR:

- [x] gemfile:twitter
- [x] twitter helper (caching (to avoid reaching twitter rate limits)
- [x] index twitter view
- [x] twitter css (twitter design as discussed in call: Profil-Header: Picture, Link to twitter + twitter_handle; removed picture and twitter_handle from individual tweet, heading aligns at the top, only the last 3 tweets are shown)
- [x] script to generate bearer token
- [x] script to invalidate generated bearer token
- [x] documentation (Readme + Doc)

1 files changed, 2 insertions, 1 deletions

diff --git a/README.md b/README.md
index e68c117..923b239 100644
--- a/README.md
+++ b/README.md
@@ -9,6 +9,7 @@ The LEAP Web App provides the following functions:
 * Webfinger access to user’s public keys
 * Email aliases and forwarding
 * Localized and Customizable documentation
+* Display of status updates from Twitter (access to tweets via Twitter API)
 
 Written in: Ruby, Rails.
 
@@ -36,6 +37,7 @@ For more information, see these files in the ``doc`` directory:
 * DEPLOY -- for notes on deployment.
 * DEVELOP -- for developer notes.
 * CUSTOM -- how to customize.
+* TWITTER_FEED -- how to use it.
 
 External docs:
 
@@ -186,4 +188,3 @@ Known problems
   attacks. These are very hard to prevent, because our protocol is
   designed to allow query of a user database via proxy in order to
   provide network perspective.
-