MAGETWO-89260: Fix Travis build issues

- fix integration tests and static test

Author: Joan He

dev/tests/integration/framework/tests/unit/testsuite/Magento/Test/Bootstrap/EnvironmentTest.php

@@ -77,4 +77,4 @@ public function testEmulateSession()
         $this->assertSame($sessionVars, $this->_getSessionVars(), 'Super-global $_SESSION must not be affected.');
         $this->assertNotEmpty(session_id(), 'Global session identified has to be emulated.');
     }
-}
+}

dev/tests/integration/testsuite/Magento/Framework/Session/SaveHandlerTest.php

@@ -7,7 +7,6 @@
 
 use Magento\Framework\App\DeploymentConfig;
 use Magento\Framework\Session\Config\ConfigInterface;
-use Magento\Framework\Session\SaveHandler;
 use Magento\Framework\App\ObjectManager;
 
 class SaveHandlerTest extends \PHPUnit\Framework\TestCase
@@ -55,10 +54,6 @@ public function testSetSaveHandler($deploymentConfigHandler, $iniHandler)
             $expected,
             ObjectManager::getInstance()->get(ConfigInterface::class)->getOption('session.save_handler')
         );
-
-        if ($iniHandler && isset($this->originalSaveHandler) && $iniHandler != $this->originalSaveHandler) {
-            ini_set('session.save_handler', $this->originalSaveHandler);
-        }
     }
 
     public function saveHandlerProvider()

lib/internal/Magento/Framework/Image/Adapter/AbstractAdapter.php

@@ -301,9 +301,12 @@ public function getImageType()
         if ($this->_fileType) {
             return $this->_fileType;
         } else {
-            list($this->_imageSrcWidth, $this->_imageSrcHeight, $this->_fileType) = getimagesize($this->_fileName);
-            return $this->_fileType;
+            if ($this->_canProcess()) {
+                list($this->_imageSrcWidth, $this->_imageSrcHeight, $this->_fileType) = getimagesize($this->_fileName);
+                return $this->_fileType;
+            }
         }
+        return null;
     }
 
     /**

lib/internal/Magento/Framework/Session/SaveHandler.php

@@ -7,7 +7,6 @@
 
 use Magento\Framework\App\DeploymentConfig;
 use Magento\Framework\App\ObjectManager;
-use Magento\Framework\Exception\SessionException;
 use Magento\Framework\Session\Config\ConfigInterface;
 
 /**
@@ -53,7 +52,7 @@ public function __construct(
 
         try {
             $connection = $saveHandlerFactory->create($saveMethod);
-        } catch (SessionException $e) {
+        } catch (\LogicException $e) {
             $connection = $saveHandlerFactory->create($default);
             $this->setSaveHandler($default);
         }