return to matsim 11 for now. matsim 12 depends on apache commons compressor which clashes with same package in the josm dependency

Add GitLab CI configuration

Update GTFS-lib from v1.1.0 to v5.0.7

All occurences of `com.vividsolutions.jts.*` are replaced by `org.locationtech.jts.*`. Return to using the `geotools` JOSM plugin to provide the GeoTools library.

Starting with JTS 1.15.0, the project is now maintained by the LocationTech working group of the Eclipse foundation and no longer by Vivid Solutions. Therefore the package names changed from `com.vividsolutions.jts.*` to `org.locationtech.jts.*`. See also https://github.com/locationtech/jts/blob/8297beca5255df7ad9909f24ec16b3d7983e82eb/MIGRATION.md#jts-115 .
The JOSM plugin `jts` (dependency of the `geotools` plugin) uses a recent enough version now, so we can use the `jts` and `geotools` JOSM plugins to provide these two libraries.

explicitly use trusty ubuntu distribution to fix current travis build

add geotools again as dependency (as already described in #93 and as a possible fix for bug reported in #106

change to 11.0-SNAPSHOT for the otfvis extension as the stable version does not seem to work well with Java 8 (ust a suspicion for now)

change to matsim 11 stable; remove geotoools plugin dependency which uses old geotools version. fixes shape file export for matsim networks

 use transitive jts/geotools dependency of matsim as it updated to a new version. somehow messy as two versions are in use now as the geotools/jts josm plugins seem to use older versions and are used to convert osm primitives to geometries. will possibly revise this later

Add missing JavaFX Plugin dependency