Skip other spec suites on JRuby 2.0 mode.

It appears to be much, much slower. For example, for
rspec-support, the JRuby builds for 1.8 and 1.9 modes
were 3:26 and 3:51, but 9:44 for 2.0 mode. There is
similar slowness for the other repos.

travis/script/functions.sh

@@ -55,9 +55,13 @@ function run_cukes {
 function run_specs_one_by_one {
   echo "Running each spec file, one-by-one..."
 
-  for file in `find spec -iname '*_spec.rb'`; do
-    bin/rspec $file -b --format progress
-  done
+  if is_mri; then
+    for file in `find spec -iname '*_spec.rb'`; do
+      bin/rspec $file -b --format progress
+    done
+  else
+    echo "Skipping one-by-one specs on non-MRI rubies as they tend to have long boot times"
+  fi
 }
 
 function run_spec_suite_for {
@@ -114,18 +118,22 @@ function check_style_and_lint {
 }
 
 function run_all_spec_suites {
-  fold "one-by-one specs" run_specs_one_by_one
-  fold "rspec-core specs" run_spec_suite_for "rspec-core"
-  fold "rspec-expectations specs" run_spec_suite_for "rspec-expectations"
-  fold "rspec-mocks specs" run_spec_suite_for "rspec-mocks"
-
-  if is_mri; then
-    fold "rspec-rails specs" run_spec_suite_for "rspec-rails"
+  if is_jruby_20_mode; then
+    echo "Skipping other spec suites for JRuby 2.0 mode because it is so much slower"
   else
-    echo "Skipping rspec-rails specs on non-MRI rubies"
-  fi
+    fold "one-by-one specs" run_specs_one_by_one
+    fold "rspec-core specs" run_spec_suite_for "rspec-core"
+    fold "rspec-expectations specs" run_spec_suite_for "rspec-expectations"
+    fold "rspec-mocks specs" run_spec_suite_for "rspec-mocks"
 
-  if rspec_support_compatible; then
-    fold "rspec-support specs" run_spec_suite_for "rspec-support"
+    if is_mri; then
+      fold "rspec-rails specs" run_spec_suite_for "rspec-rails"
+    else
+      echo "Skipping rspec-rails specs on non-MRI rubies"
+    fi
+
+    if rspec_support_compatible; then
+      fold "rspec-support specs" run_spec_suite_for "rspec-support"
+    fi
   fi
 }

travis/script/predicate_functions.sh

@@ -8,6 +8,14 @@ function is_mri {
   fi;
 }
 
+function is_jruby_20_mode {
+  if [ "$JRUBY_OPTS" = "--2.0" ]; then
+    return 0
+  else
+    return 1
+  fi
+}
+
 function is_mri_192 {
   if is_mri; then
     if ruby -e "exit(RUBY_VERSION == '1.9.2')"; then