Possible compatibility issue with jackson 2.7

[tarehart]

Hello,

Upon upgrading jackson-core, jackson-databind, and jackson-annotations to 2.7.0 or 2.7.1, I am no longer able to sign in successfully with google.

I'm seeing this issue with both spring-social-google:1.0.0.RELEASE
and spring-social-google:1.0.0.BUILD-SNAPSHOT.

Here's a stack trace:

java.lang.IllegalArgumentException: Unrecognized Type: [null]
        at com.fasterxml.jackson.databind.type.TypeFactory._fromAny(TypeFactory.java:1109)
        at com.fasterxml.jackson.databind.type.TypeFactory.constructType(TypeFactory.java:566)
        at com.fasterxml.jackson.databind.type.TypeFactory.constructType(TypeFactory.java:602)
        at org.springframework.http.converter.json.AbstractJackson2HttpMessageConverter.getJavaType(AbstractJackson2HttpMessageConverter.java:281)
        at org.springframework.http.converter.json.AbstractJackson2HttpMessageConverter.canRead(AbstractJackson2HttpMessageConverter.java:138)
        at org.springframework.http.converter.json.AbstractJackson2HttpMessageConverter.canRead(AbstractJackson2HttpMessageConverter.java:133)
        at org.springframework.web.client.RestTemplate$AcceptHeaderRequestCallback.doWithRequest(RestTemplate.java:681)
        at org.springframework.web.client.RestTemplate$HttpEntityRequestCallback.doWithRequest(RestTemplate.java:745)
        at org.springframework.web.client.RestTemplate.doExecute(RestTemplate.java:569)
        at org.springframework.web.client.RestTemplate.execute(RestTemplate.java:532)
        at org.springframework.web.client.RestTemplate.exchange(RestTemplate.java:450)
        at org.springframework.social.google.connect.GoogleOAuth2Template.postForAccessGrant(GoogleOAuth2Template.java:48)
        at org.springframework.social.oauth2.OAuth2Template.exchangeForAccess(OAuth2Template.java:144)
        at org.springframework.social.connect.web.ConnectSupport.completeConnection(ConnectSupport.java:160)
        at org.springframework.social.connect.web.ProviderSignInController.oauth2Callback(ProviderSignInController.java:228)

To work around this, I am forcing jackson to version 2.6.5.

P.S. Thanks for writing and maintaining this library, it works great!