Fix irritating golint warnings.

Author: tintoy

compute/account.go

@@ -65,7 +65,7 @@ func (client *Client) GetAccount() (*Account, error) {
 	}
 
 	if statusCode == 401 {
-		return nil, fmt.Errorf("Cannot connect to compute API (invalid credentials).")
+		return nil, fmt.Errorf("cannot connect to compute API (invalid credentials).")
 	}
 
 	account := &Account{}

compute/ipblock.go

@@ -340,7 +340,7 @@ func calculateBlockAddresses(block PublicIPBlock) ([]string, error) {
 
 	baseAddressComponents := strings.Split(block.BaseIP, ".")
 	if len(baseAddressComponents) != 4 {
-		return addresses, fmt.Errorf("Invalid base IP address '%s'.", block.BaseIP)
+		return addresses, fmt.Errorf("invalid base IP address '%s'.", block.BaseIP)
 	}
 	baseOctet, err := strconv.Atoi(baseAddressComponents[3])
 	if err != nil {