added contribution guidelines

CHANGELOG.md

 Upcoming version:
 -----------------
+  - added contribution guidelines (Nikolaus Krismer)
   - moving gradle changelog tasks to separate buildscript (Nikolaus Krismer)
-
-Version v0.5.1:
----------------
   - fixing problems in changelog generation (again) (Nikolaus Krismer)
-  - Merge branch 'master' of git@dbis-git.uibk.ac.at:krismer/isochrone-vm.git (Nikolaus Krismer)
   - calling grgit add before grgit commit (by now push is empty) (Nikolaus Krismer)
   - not commiting changelogs in jenkins without changes :-) (Nikolaus Krismer)
   - improving gradle changelog mechanism (excluding jenkins commits) (Nikolaus Krismer)
@@ -16,6 +13,9 @@ Version v0.5.1:
   - fixing problems with gradle's clean task (Nikolaus Krismer)
   - fixing invalid clean task definition (Nikolaus Krismer)
   - adding removal of CHANGELOG to clean task (Nikolaus Krismer)
+
+Version v0.5.1:
+---------------
   - removed hard-coded version from gradle (is set using scmversion plugin) (Nikolaus Krismer)
   - added density generation for synthethic networks (Nikolaus Krismer)
   - removed pgRouting / osm2pgrouting from files (not needed and never used) (Nikolaus Krismer)
@@ -40,7 +40,6 @@ Version v0.5.0:
   - geoserver version update (Nikolaus Krismer)
   - always adding pg_procedures to created database (not only when postgis is installed) (Nikolaus Krismer)
   - added installation of phpLiteAdmin and spatialite (Nikolaus Krismer)
-  - Merge branch 'master' of git@dbis-git.uibk.ac.at:krismer/isochrone-vm.git (Nikolaus Krismer)
   - source profile in init script so it works without problems in centos 6 with the service command (Nikolaus Krismer)
   - Fixed tomcat startup message (root)
   - creating directories needed by script at the beginning (Nikolaus Krismer)
@@ -48,7 +47,7 @@ Version v0.5.0:
   - updating gradle (to v2.4) (Nikolaus Krismer)
   - java version update (Nikolaus Krismer)
   - added postgresql.conf (should fix empty log file and unexpected locale) (Nikolaus Krismer)
-  - not sharing vagrant's home directoy anymore -> writing bootstrap logs to dedicated log folder  -> should fix the problem where vagrant asks for password on "vagrant up" (Nikolaus Krismer)
+  - not sharing vagrant's home directoy anymore -> writing bootstrap logs to dedicated log folder -> should fix the problem where vagrant asks for password on "vagrant up" (Nikolaus Krismer)
   - adding synced folders for log files (log files in home and in postgresql-log directory) (Nikolaus Krismer)
   - changed path to nexus repository (dbis dns name changed) (Nikolaus Krismer)
   - improved db setup (log file handling) so test can get timings from postgresql log file (Nikolaus Krismer)
@@ -58,7 +57,7 @@ Version v0.5.0:
 Version v0.4.1:
 ---------------
   - updating to java8u40 (Nikolaus Krismer)
-  - removed support for fedora 20 some version updates added isochrone-tool artifact download  -> generating synthetic networks in datbase now (Nikolaus Krismer)
+  - removed support for fedora 20 some version updates added isochrone-tool artifact download -> generating synthetic networks in datbase now (Nikolaus Krismer)
   - added documentation about VT-x/AMD-V in virtualbox (Nikolaus Krismer)
   - upgrade to gradle version 2.3 (Nikolaus Krismer)
   - fixed typo reworked profile.d exports (added missing postgresql to path) (Nikolaus Krismer)

CONTRIBUTING.md

+# Contribution Guide
+
+This document describes some points about the contribution process.
+
+## Request an account
+
+For creating issues and/or forking the project you will need a gitlab user-account at dbis-git.uibk.ac.at.
+Write an e-mail to nikolaus.krismer@uibk.ac.at in order to request such an account.
+
+## Issues / Features
+
+ - Check open issues for what you want.
+ - If there is an open issue, comment on it, otherwise open an issue describing your bug or feature with use cases.
+ - Discussion happens on the issue about how to solve your problem.
+ - After the discussion took place you can create a Pull Request (see below) or wait for a developer to do so.
+
+## Pull requests
+
+We love pull requests. Here's a quick guide:
+
+ 1. Fork the project you want to contribute to
+ 2. Create a new feature branch
+ 3. Commit your changes
+ 4. Push to the branch
+ 5. Create a new Pull Request
+
+Please make sure you add at lest one test for your change and that all tests are passed.
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