Fix CI scripts; use dotnet everywhere for testing; remove before-install-linux-csharp.sh, run-tests-csharp.sh

Author: KvanTTT

.travis.yml

@@ -147,7 +147,9 @@ matrix:
       stage: smoke-test
     - os: linux
       jdk: openjdk8
-      env: TARGET=csharp
+      env:
+        - TARGET=dotnet
+        - GROUP=MAIN
       stage: main-test
     - os: linux
       jdk: openjdk8
@@ -162,21 +164,18 @@ matrix:
       stage: main-test
     - os: linux
       jdk: openjdk8
-      dist: trusty
       env:
         - TARGET=dotnet
         - GROUP=LEXER
       stage: extended-test
     - os: linux
       jdk: openjdk8
-      dist: trusty
       env:
         - TARGET=dotnet
         - GROUP=PARSER
       stage: extended-test
     - os: linux
       jdk: openjdk8
-      dist: trusty
       env:
         - TARGET=dotnet
         - GROUP=RECURSION

.travis/before-install-linux-csharp.sh

@@ -2,9 +2,9 @@
 
 set -euo pipefail
 
-# install dotnet
-sudo sh -c 'echo "deb [arch=amd64] https://apt-mo.trafficmanager.net/repos/dotnet-release/ trusty main" > /etc/apt/sources.list.d/dotnetdev.list'
-sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 417A0893
-sudo apt-get update
-sudo apt-get --allow-unauthenticated install dotnet-dev-1.0.4
-
+wget https://packages.microsoft.com/config/ubuntu/16.04/packages-microsoft-prod.deb -O packages-microsoft-prod.deb
+sudo dpkg -i packages-microsoft-prod.deb
+sudo apt-get update; \
+  sudo apt-get install -y apt-transport-https && \
+  sudo apt-get update && \
+  sudo apt-get install -y dotnet-sdk-3.1