Run MiMa on Travis CI

Ref 62d1ab0249
Ref https://github.com/coursier/coursier/issues/1174

build.sbt

@@ -39,6 +39,7 @@ lazy val `lm-coursier-shaded` = project
   .enablePlugins(ShadingPlugin)
   .settings(
     shared,
+    Mima.settings,
     unmanagedSourceDirectories.in(Compile) := unmanagedSourceDirectories.in(Compile).in(`lm-coursier`).value,
     shading,
     shadingNamespace := "lmcoursier.internal.shaded",

scripts/travis.sh

@@ -16,7 +16,8 @@ sbtShading() {
 runLmCoursierTests() {
   # publishing locally to ensure shading runs fine
   ./metadata/scripts/with-test-repo.sh sbt \
-    ++$TRAVIS_SCALA_VERSION \
+    ++$TRAVIS_SCALA_VERSION! \
+    mimaReportBinaryIssues \
     lm-coursier-shaded/publishLocal \
     lm-coursier/test \
     "sbt-lm-coursier/scripted shared-$TEST_GROUP/*"