Add more unit tests for the sdk and some refactoring (#128)

* Adding more unit tests for the sdk and some refactoring
   - Added more tests in the sdk
   - Removed some logs that are not required.
   - Removed a duplicate function
* Updating go.sum to fix the build failure
* Fix build error as reported in golang/lint#436

Signed-off-by: Prativa Bawri<bawrip@vmware.com>

.travis.yml

@@ -7,7 +7,7 @@ env:
   - GO111MODULE=on
 
 before_install:
-  - go get -u golang.org/x/lint/golint
+  - go get golang.org/x/lint/golint
 
 script:
   - make check race release

go.sum

@@ -11,13 +11,11 @@ github.com/bgentry/speakeasy v0.1.0/go.mod h1:+zsyZBPWlz7T6j88CTgSN5bM796AkVf0kB
 github.com/blang/semver v3.5.1+incompatible h1:cQNTCjp13qL8KC3Nbxr/y2Bqb63oX6wdnnjpJbkM4JQ=
 github.com/blang/semver v3.5.1+incompatible/go.mod h1:kRBLl5iJ+tD4TcOOxsy/0fnwebNt5EWlYSAyrTnjyyk=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
-github.com/dghubble/sling v1.1.0 h1:DLu20Bq2qsB9cI5Hldaxj+TMPEaPpPE8IR2kvD22Atg=
 github.com/dghubble/sling v1.1.0/go.mod h1:ZcPRuLm0qrcULW2gOrjXrAWgf76sahqSyxXyVOvkunE=
 github.com/go-ini/ini v1.28.2 h1:drmmYv7psRpoGZkPtPKKTB+ZFSnvmwCMfNj5o1nLh2Y=
 github.com/go-ini/ini v1.28.2/go.mod h1:ByCAeIL28uOIIG0E3PJtZPDL8WnHpFKFOtgjp+3Ies8=
 github.com/golang/protobuf v0.0.0-20170920220647-130e6b02ab05 h1:Kesru7U6Mhpf/x7rthxAKnr586VFmoE2NdEvkOKvfjg=
 github.com/golang/protobuf v0.0.0-20170920220647-130e6b02ab05/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
-github.com/google/go-querystring v0.0.0-20170111101155-53e6ce116135 h1:zLTLjkaOFEFIOxY5BWLFLwh+cL8vOBW4XJ2aqLE/Tf0=
 github.com/google/go-querystring v0.0.0-20170111101155-53e6ce116135/go.mod h1:odCYkC5MyYFN7vkCjXpyrEuKhc/BUO6wN/zVPAxq5ck=
 github.com/gopherjs/gopherjs v0.0.0-20181103185306-d547d1d9531e/go.mod h1:wJfORRmW1u3UXTncJ5qlYoELFm8eSnnEO6hX4iZ3EWY=
 github.com/hashicorp/errwrap v0.0.0-20141028054710-7554cd9344ce h1:prjrVgOk2Yg6w+PflHoszQNLTUh4kaByUcEWM/9uin4=
@@ -88,5 +86,4 @@ google.golang.org/genproto v0.0.0-20171002232614-f676e0f3ac63 h1:yNBw5bwywOTguAu
 google.golang.org/genproto v0.0.0-20171002232614-f676e0f3ac63/go.mod h1:JiN7NxoALGmiZfu7CAH4rXhgtRTLTxftemlI0sWmxmc=
 google.golang.org/grpc v1.6.0 h1:vaySXtNtPrLJFCiET8QXtfBrqq16ynklmFGaZwLcd1M=
 google.golang.org/grpc v1.6.0/go.mod h1:yo6s7OP7yaDglbqo1J04qKzAhqBH6lvTonzMVmEdcZw=
-gopkg.in/jarcoal/httpmock.v1 v1.0.0-20170412085702-cf52904a3cf0 h1:wQvcxZY1FNzBQm8MA4aUNdK4nozflCum8cqis1bUOw4=
 gopkg.in/jarcoal/httpmock.v1 v1.0.0-20170412085702-cf52904a3cf0/go.mod h1:d3R+NllX3X5e0zlG1Rful3uLvsGC/Q3OHut5464DEQw=